Conductive Paste Bonding Strength via Composite Metal Powders
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Solution Overview
Problem
Current manufacturing processes and conductive pastes often fail to provide sufficient bonding between electrical components and substrates, leading to unsatisfactory construction of electronic devices.
Innovation Solution
A conductive paste comprising a mixture of metal powders with specific particle diameter ranges (10-150 nm and 151-500 nm) and a solvent, applied to a substrate, followed by heating to achieve strong bonding between the electrical component and the substrate, with optional polymer addition for enhanced properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conductive paste is used for bonding electrical components to substrates, then the manufacturing process can be completed, but the bonding strength is insufficient and reliability is poor
Solution Approach 1:
The conductive paste uses a composite metal powder system combining spherical silver particles (1-10 μm) with nanometer-scale metal particles (10-500 nm). This composite structure enables the paste to achieve both strong bonding strength through nanometer particle penetration and good manufacturability through the spherical macro particles that facilitate smooth application and sintering.
Solution Approach 2:
The invention introduces nanometer-scale metal particles (10-500 nm) into the conductive paste formulation, representing a significant parameter change in particle size distribution. This parameter change enables the paste to penetrate oxide layers and form strong metallurgical bonds, dramatically improving bonding strength while maintaining manufacturing feasibility.
2Strength
If heating is applied to bond the electrical component to the substrate, then joining is achieved, but heat damage may occur to sensitive components
Solution Approach 1:
The inclusion of nanometer-scale metal particles (10-500 nm) in the conductive paste enables effective bonding at lower temperatures compared to conventional pastes. The nanometer particles facilitate cold welding and reduce the energy required for bonding, thereby achieving strong joints while minimizing heat damage to temperature-sensitive electrical components.
Solution Approach 2:
The composite structure of spherical silver particles combined with nanometer metal particles creates a multi-scale bonding mechanism. The nanometer particles provide low-temperature bonding capability through surface diffusion and cold welding, while the spherical particles maintain structural integrity, enabling strong bonds with reduced thermal exposure.
3Duration of action of stationary object
If conventional metal powder is used in conductive paste, then the paste can be applied, but the bonding durability under thermal cycling is insufficient
Solution Approach 1:
The conductive paste combines spherical silver particles (1-10 μm) with nanometer-scale metal particles (10-500 nm) to create a composite structure that excels under thermal cycling. The nanometer particles form a flexible, fine-grained bonding network that accommodates thermal expansion differences, while the spherical silver particles provide structural stability, together achieving superior bonding durability and thermal cycling resistance.
Solution Approach 2:
The nanometer-scale metal particles (10-500 nm) are distributed throughout the conductive paste to create localized regions of enhanced bonding capability. These fine particles concentrate at bonding interfaces and provide localized flexibility and adhesion, enabling the joint to withstand repeated thermal expansion and contraction without failure.
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 conductive paste effectively bonds electrical components to substrates, demonstrating high bonding strength and durability through thermal cycling tests, with improved adherence and reduced heat damage.
Implementation Method 1
heating the conductive paste to join the electrically conductive layer and the electrical component
Data Source
AI summary
The present invention relates to a conductive paste for bonding that comprises a metal powder and a solvent, wherein the metal powder comprises a first metal powder having a particle diameter (D50) of 10 to 150 nm and a second metal powder having a particle diameter (D50) of 151 to 500 nm. The paste is useful for manufacturing an electronic device comprising a substrate with an electrically conductive layer and an electrical or electronic component, which are reliably bonded together using the paste.