Donor Substrate Buffer Layer Mitigates Thermal Damage in Laser Transfer

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Solution Overview

Problem

Conventional laser induced thermal imaging processes for organic light emitting display devices often result in thermal damage to the transfer layer and substrate due to excessive heat transfer, which limits the scalability and reliability of the manufacturing process.

Innovation Solution

A donor substrate is designed with a base substrate, a light to heat conversion layer, a buffer layer featuring porous layers with low thermal conductivity, and an intermediate layer to mitigate heat transfer and prevent damage, allowing for the formation of organic layers with reduced thermal stress and impurity exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional laser induced thermal imaging process is used to form organic layers, then the transfer layer can be partially transferred to form organic layer patterns, but thermal energy damages the transfer layer or the display substrate

Engineering Contradiction:

Improveorganic layer pattern formationVSAvoidthermal damage to transfer layer and substrate

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

A buffer layer is introduced as an intermediary between the light to heat conversion layer and the transfer layer. This buffer layer absorbs and dissipates excess thermal energy, preventing direct thermal damage to the transfer layer and substrate while still allowing the laser-induced thermal imaging process to form organic layer patterns effectively

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer layer is designed with a porous structure containing multiple pores. This porous configuration increases the surface area for heat dissipation and provides thermal insulation pathways, enabling the buffer layer to effectively reduce thermal energy transmission to the transfer layer and substrate while maintaining structural integrity

Inventive Principle:

Principle #31Porous materials

2Manufacturing precision

If a deposition process is used to form organic layers, then organic layers can be formed, but it is hard to apply to devices with relatively large area due to micro-dimensioned metal mask requirements

Engineering Contradiction:

Improveorganic layer formationVSAvoiddisplay device area

Core Design Contradiction:

Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The mechanical deposition process using micro-dimensioned metal masks is replaced with a laser-induced thermal imaging process. This substitution eliminates the area limitations imposed by mask dimensions, enabling the formation of organic layers on large-area display devices while maintaining manufacturing precision through laser beam control

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If ink-jet printing process is used to form organic layers, then organic layers can be formed, but limited materials can be used except for the light emitting layer and additional structures are required on the substrate

Engineering Contradiction:

Improveorganic layer formationVSAvoidmaterial selection flexibility

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The ink-jet printing process is replaced with a laser-induced thermal imaging process using a transfer layer. This substitution expands material selection flexibility because the transfer layer can be fabricated with diverse materials using deposition techniques, and then transferred to the substrate, eliminating the material limitations of ink-jet printing while also eliminating the need for additional substrate structures

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution effectively reduces thermal damage to the transfer layer and substrate, enabling the formation of high-resolution organic layer patterns with improved uniformity and flexibility, thus enhancing the manufacturing efficiency and reliability of organic light emitting display devices.

Implementation Method 1

a light to heat conversion layer, configured to convert light energy into thermal energy in response to irradiation by a laser beam

Methodology Applied

Scientific EffectLight to heat conversion: Absorption (EM radiation)

Implementation Method 2

a buffer layer, configured to reduce transfer of the thermal energy generated by the light to heat conversion layer to the organic layer pattern. The buffer layer may include at least one porous layer having a plurality of pores

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS8728704B2Donor substrates, laser induced thermal imaging methods using donor substrates and methods of manufacturing organic light emitting display devices using donor substrates

Publication Date: 2014.05.20 SAMSUNG DISPLAY CO LTD

AI summary

A donor substrate includes a base substrate, a light to heat conversion layer, a buffer layer and a transfer layer. The light to heat conversion layer may be disposed on the base substrate. The buffer layer may be disposed on the light to heat conversion layer. The buffer layer may include at least one porous layer having a plurality of pores. The transfer layer may be disposed on the buffer layer.