Amorphous Silver Bonding Film for Low-Temperature Void-Free Joining

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing bonding methods using lead-free solder require complex mixing of components, are laborious, and costly, while also facing challenges with thermal stress and void formation at bonding interfaces, especially at low temperatures.

Innovation Solution

A bonding material comprising an amorphous silver film, which is formed from a silver layer through heating, allowing for easy and cost-effective bonding between targets at lower temperatures by crystallizing into a crystalline silver film, reducing thermal stress and void formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If lead-free solder is used for bonding, then environmental protection is improved, but thermal stress damage and void formation occur at bonding interfaces due to higher melting point

Engineering Contradiction:

Improveenvironmental protectionVSAvoidbonding interface quality

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention changes the material parameters by using a paste containing metal nanoparticles instead of traditional lead-free solder, enabling bonding at lower temperatures while maintaining environmental protection benefits

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The bonding paste is formulated as a composite material containing metal nanoparticles, organic dispersant, dispersant scavenger, and volatile organic component, which works together to achieve low-temperature bonding without void formation

Inventive Principle:

Principle #40Composite materials

2Temperature

If a paste containing multiple components is used for low-temperature bonding, then bonding temperature is reduced, but preparation becomes laborious and costly

Engineering Contradiction:

Improvebonding temperatureVSAvoidpaste preparation simplicity

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The invention combines multiple functional components (metal nanoparticles, organic dispersant, dispersant scavenger, and volatile organic component) into a single integrated paste formulation, simplifying the manufacturing process while maintaining low-temperature bonding capability

Inventive Principle:

Principle #5Merging (Combining)

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

Enables favorable and easy bonding in low-temperature environments without the need for complex mixing, reducing costs and preventing damage to bonding targets, while ensuring strong and reliable connections.

Implementation Method 1

forming an amorphous silver film from the silver layer by heating the silver layer

Methodology Applied

Scientific EffectCrystallization: Crystallisation

Data Source

PatentUS11273525B2Bonding material, method for producing bonding material, and method for producing bonding structure

Publication Date: 2022.03.15 OSAKA UNIVERSITY

AI summary

A bonding material (10) of the present invention includes an amorphous silver film (12).