Optical Laminate Metal Adhesion Layer for Uniform Sputtering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge lies in achieving stable and firm adhesion between a resin substrate and an oxide optical layer in optical multilayer films, particularly when using a sputtering method, due to differences in bond types and surface conditions, which leads to issues like target oxidation and inconsistent film formation.

Innovation Solution

The use of a metal adhesion layer with a melting point between 100°C and 700°C, having a thickness of 8 nm or less, is introduced between the transparent substrate and the optical layer to enhance adhesion, utilizing a sputtering method for continuous film formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a sputtering method is used to form an optical multilayer film on a resin substrate, then a wide variety of materials can be laminated many times with uniform film thickness, but adhesion between the resin substrate and oxide thin film becomes poor due to different bond types

Engineering Contradiction:
Improvefilm thickness uniformityVSAvoidadhesion between substrate and thin film
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

An adhesion layer made of metal material with melting point of 700°C or less is introduced as an intermediary between the resin substrate and the oxide optical thin film. This adhesion layer serves as a mediator that bridges the interface between the organic resin substrate (with covalent bonds) and the inorganic oxide film (with ionic bonds), enabling strong adhesion through compatible bonding characteristics while maintaining the benefits of sputtering deposition.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the sputtering method is used for continuous film formation, then large area films can be formed at one time, but target oxidation occurs and discharge cannot be sustained

Engineering Contradiction:
Improvecontinuous film formation capabilityVSAvoidstable discharge
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The melting point parameter of the adhesion layer material is controlled to be 700°C or less. This parameter change enables the adhesion layer to remain stable during sputtering deposition without causing target oxidation issues, while still providing effective adhesion between the resin substrate and the subsequent oxide optical thin film layers.

Inventive Principle:
Principle #35Parameter changes

3Strength

If a metal adhesion layer with melting point of 700°C or less is used, then strong adhesion is achieved, but the film thickness must be controlled to 8 nm or less to maintain optical properties

Engineering Contradiction:
Improveadhesion strengthVSAvoidfilm thickness control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

Both the melting point parameter (≤700°C) and the film thickness parameter (≤8 nm) of the adhesion layer are precisely controlled. This dual parameter control ensures that the adhesion layer provides strong bonding between the resin substrate and oxide film while maintaining the optical properties of the overall multilayer structure by minimizing light absorption and interference.

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

This approach enables stable and strong adhesion between the transparent substrate and optical layer, ensuring uniform film formation over large areas, maintaining optical properties and reducing light absorption.

Implementation Method 1

a sputtering method, which uses plasma in a vacuum, has various advantages such as being able to form a film even with materials with high melting points and ensuring film thickness uniformity

Methodology Applied
Scientific EffectSputtering: Sputtering

Implementation Method 2

a sputtering method, which uses plasma in a vacuum

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 3

a method of forming a film in a vacuum can laminate a wide variety of materials many times

Methodology Applied
Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Data Source

PatentEP4184223B1Optical laminate and article
Publication Date: 2025.08.13 DEXERIALS CORP
  • EP4184223B1 patent drawingFigure 1

AI summary

This optical laminate includes a transparent substrate; an adhesion layer provided on at least one surface of the transparent substrate; and an optical layer provided on a surface of the adhesion layer on a side opposite to the transparent substrate, wherein the adhesion layer is formed of a metal material, and the metal material has a melting point in a range of 100°C or more and 700°C or less.