Multiscale Conductive Paste for Rapid Low-Complexity Sintering
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Solution Overview
Problem
Existing sintering processes for electronic components require high temperatures, prolonged manufacturing times, and complex equipment, leading to increased costs and complexity.
Innovation Solution
A conductive paste comprising specific metal powders with varying particle sizes and a solvent composition, allowing for rapid sintering without additional drying steps, thereby reducing manufacturing complexity and time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional sintering processes are used to join electronic components, then strong sintered bonds with high temperature resistance are achieved, but manufacturing time increases and process complexity increases due to required high temperatures and die bond equipment
Solution Approach 1:
The patent changes the particle size parameters of metal powders (D10: 10-100 nm, D50: 500-1500 nm, D90: 3000-5500 nm) and chemical composition parameters (metal powder 70-90 wt%, organic vehicle 10-30 wt%) to enable sintering at lower temperatures and shorter times while maintaining bond strength. This parameter optimization allows rapid sintering without sacrificing connection integrity.
Solution Approach 2:
The patent uses a composite metal powder system combining multiple particle sizes (nanoparticles 10-100 nm, fine particles 500-1500 nm, and coarse particles 3000-5500 nm) to create a multi-scale composite structure. This composite approach enables both rapid sintering and strong bonds by combining the high reactivity of nanoparticles with the structural integrity provided by larger particles.
2Reliability
If conventional sintering processes are used to join electronic components, then reliable electrical and thermal contact is achieved, but device complexity increases due to required die bond equipment
Solution Approach 1:
The patent optimizes the chemical composition parameters including metal powder type (silver, copper, aluminum, or alloys), particle size distribution (D10, D50, D90 ranges), and organic vehicle composition to enable sintering without die bond equipment. These parameter changes allow the paste to self-sinter and form reliable electrical and thermal contacts through controlled oxidation and diffusion mechanisms.
Solution Approach 2:
The patent replaces the mechanical die bond pressing system with a chemical-thermal sintering process. Instead of requiring high mechanical pressure equipment, the invention uses controlled thermal treatment that activates diffusion and bonding through the optimized metal powder composition and particle size distribution, thereby eliminating complex mechanical equipment while maintaining connection reliability.
3Productivity
If rapid sintering is implemented to reduce manufacturing time, then productivity increases, but manufacturing precision may deteriorate due to potential void formation
Solution Approach 1:
The patent employs a composite particle size system (combining 10-100 nm nanoparticles, 500-1500 nm fine particles, and 3000-5500 nm coarse particles) that enables rapid sintering while preventing void formation. The nanoparticles fill interstices between larger particles, creating a dense packed structure that sinteres quickly without trapping voids, thus maintaining manufacturing precision during high-speed processing.
Solution Approach 2:
The patent applies local quality by having different particle sizes serve different functions: nanoparticles (10-100 nm) provide high reactivity and fill void spaces, fine particles (500-1500 nm) form the primary bonding network, and coarse particles (3000-5500 nm) provide structural framework. This localized functional distribution enables rapid sintering while maintaining density and preventing void formation throughout the joint.
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 enables effective sintered connections with minimal void formation and improved processing rates, achieving shear strengths of at least 20 MPa to 60 MPa without the need for die bond equipment.
Implementation Method 1
Sintered connections provide a sintered bond between parts having high temperature resistance while ensuring good electrical and thermal contact
Implementation Method 2
a first metal powder having a having a D50 ranging from about 500 nm to about 1,500 nm, a second metal powder having a D50 ranging from about 10 nm to about 100 nm, and a third metal powder having a D50 ranging from about 3,000 nm to about 5,500 nm
Data Source
AI summary
A conductive paste is provided. The conductive paste includes a metal particulate material having a first metal powder having a having a D50 ranging from about 500 nm to about 1,500 nm, a second metal powder having a D50 ranging from about 10 nm to about 100 nm, and a third metal powder having a D50 ranging from about 3,000 nm to about 5,500 nm. The metal paste includes a solvent composition. The weight ratio of the third metal powder to the first metal powder is greater than 1. Electronic articles are also provided.