Ionic Conductive Sealing Layer for Low-Temperature Anodic Bonding

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Solution Overview

Problem

Existing anodic bonding methods for microelectronic devices require high temperatures and voltages, which are incompatible with sensitive components that degrade under these conditions, limiting their compatibility with sensitive components like micro-batteries and organic light-emitting diodes.

Innovation Solution

The use of an ionic conductive sealing layer of formula LixPyOzNw with specific composition and thickness, which enhances lithium ion mobility, allowing for anodic bonding at lower temperatures (less than 150°C) and voltages (less than 100 volts), thereby reducing the thermal and electrical stress on sensitive components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional anodic bonding is used to achieve hermetic encapsulation, then sealing reliability is improved, but the high temperature and voltage conditions degrade sensitive components

Engineering Contradiction:

Improvesealing reliabilityVSAvoidthermal and electrical stress on components

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the bonding parameters by using a sealing layer with high ionic conductivity (containing lithium ions) that enables effective anodic bonding at reduced temperatures (<150°C) and voltages (<100V), thus maintaining sealing reliability while reducing thermal and electrical stress on sensitive components

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary sealing layer composed of lithium-containing glass or ceramic material between the substrates. This intermediary layer facilitates ion transport during bonding, enabling the bonding process to proceed at lower energy levels that are compatible with sensitive microelectronic components

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If the thickness of the sealing layer is reduced to lower bonding temperature, then compatibility with sensitive components is improved, but bonding strength may be compromised

Engineering Contradiction:

Improvebonding temperatureVSAvoidbonding strength

Core Design Contradiction:

TemperatureVSStrength

Solution Approach 1:

The patent employs a composite sealing layer combining glass and ceramic materials with specific lithium content. This composite structure provides both the low-temperature bonding capability (through lithium ion conductivity) and sufficient mechanical strength for reliable encapsulation, resolving the trade-off between bonding temperature and bonding strength

Inventive Principle:

Principle #40Composite materials

3Productivity

If high voltage is applied to achieve rapid bonding, then productivity is improved, but component degradation increases

Engineering Contradiction:

Improvebonding speedVSAvoidelectrical stress on components

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the electrical parameters by utilizing the high ionic conductivity of the lithium-containing sealing layer, which allows bonding to proceed efficiently at reduced voltages (<100V). The lithium ions facilitate rapid bond formation through enhanced ion transport, maintaining productivity while reducing electrical stress on sensitive components

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 high-performance hermetic encapsulation of sensitive microelectronic devices without degrading the components, facilitating integration and assembly while maintaining mechanical robustness and chemical compatibility.

Implementation Method 1

a sealing layer between said first faces, wherein said sealing layer comprises at least one layer of an ionic conductive material of formula LixPyOzNw

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

Anodic bonding is a method that makes it possible to assemble in a strong and permanent manner, for example, an element made of glass to a metal, a semi-conductor or an oxide. It is based on an electrochemical mechanism for the forming of covalent bonds using oxygen anions O2−

Methodology Applied

Scientific EffectAnodic bonding:

Implementation Method 3

The use of an ionic conductive sealing layer of formula LixPyOzNw with specific composition and thickness, which enhances lithium ion mobility

Methodology Applied

Scientific EffectIon mobility enhancement: Fast Ion Conductor

Data Source

PatentUS10910667B2Microelectronic device

Publication Date: 2021.02.02 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES

AI summary

This invention relates to a microelectronic device comprising: a first support, a second support, first respective faces of the first support and second support being arranged opposite, and a sealing layer between said first faces, characterized in that the sealing layer comprises at least one layer of an ionic conductive material of formula LixPyOzNw, with x strictly greater than 0 and less than or equal to 4.5, y strictly greater than 0 and less than or equal to 1, z strictly greater than 0 and less than or equal to 5.5, w greater than or equal to 0 and less than or equal to 1.