Transparent Substrate Bonding Using Sputtered Metal Oxide Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for bonding transparent substrates, such as glass and polymer films, often compromise light transmittance due to the use of organic adhesives and face challenges in bonding SiO2 surfaces using energy particle irradiation.
Innovation Solution
A method involving the formation of a thin metal oxide film on the bonding surfaces of substrates using a sputtering method with a mixed gas of inert gas and oxygen, followed by a heat treatment at 200°C or lower, to achieve strong bonding while maintaining high light transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If organic adhesives are used to bond transparent substrates, then bonding strength is achieved, but light transmittance is compromised
Solution Approach 1:
A thin film of metal oxide serves as an intermediary layer between transparent substrates, enabling bonding without organic adhesives. The metal oxide film forms chemical bonds with both substrate surfaces, providing strong adhesion while maintaining optical transparency, thus resolving the contradiction between bonding strength and light transmittance.
Solution Approach 2:
The invention changes the chemical composition parameter of the bonding interface by using metal oxide instead of organic adhesive. This parameter change transforms the bonding mechanism from organic-based adhesion to inorganic chemical bonding, achieving both high bonding strength and high light transmittance simultaneously.
2Strength
If energy particle irradiation is used to activate SiO2 surfaces for bonding, then bonding capability is improved, but light transmittance deteriorates
Solution Approach 1:
The metal oxide film acts as a mediator that facilitates bonding between SiO2 surfaces without requiring direct energy particle irradiation of the substrates. The sputtered metal oxide layer provides reactive sites for bonding while the thin film structure preserves optical transparency, avoiding the light transmittance deterioration caused by direct irradiation.
Solution Approach 2:
The invention replaces the mechanical/physical process of energy particle irradiation with a deposition process (sputtering) followed by low-temperature heat treatment. This substitution achieves surface activation and bonding capability through chemical means rather than high-energy physical means, preserving light transmittance.
3Strength
If high temperature processes are used for substrate bonding, then bonding strength is improved, but substrate damage or deformation occurs
Solution Approach 1:
The invention changes the temperature parameter of the bonding process by conducting heat treatment at 200°C or lower instead of high temperatures. This parameter change enables sufficient bonding strength to be achieved through the metal oxide film's chemical bonding mechanism without causing substrate damage or deformation associated with high-temperature processes.
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 method enables the bonding of transparent substrates with high optical transmittance and strong bonding strength, specifically achieving a light transmittance ratio of 97% or higher and a bonding strength of 0.3 J/m² or greater.
Implementation Method 1
forming a thin film of a metal oxide on both or at least one of bonding surfaces of a pair of substrates... the forming of the thin film of metal oxide on the bonding surfaces comprises forming a film by a sputtering method using a metal as a target and a mixed gas substantially consisting of an inert gas and oxygen
Implementation Method 2
contacting the bonding surfaces of the pair of substrates with each other via the thin film of the metal oxide, and performing a heat treatment at 200°C or lower after contacting the bonding surfaces
Data Source
Figure 1(a)~2
Figure 3(a)~3(c)
AI summary
[Summary] Methods of bonding substrates are provided, including forming a thin film of a metal oxide on a bonding surface of both or either of a pair of substrates, at least one of which is a transparent substrate, and contacting the bonding surfaces of the pair of substrates with each other via the thin film of the metal oxide.