Conductive Silicone Adhesive with Adjustable Thixotropy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrically conductive adhesive (ECA) compositions struggle to maintain adjustable rheology and low volume resistivity without increasing the concentration of metal particles, and often exhibit poor flexibility, which is crucial for durable electronic devices under temperature variations.
Innovation Solution
A curable silicone composition with a total silver concentration of 50-60 weight percent and an adjustable thixotropic index, incorporating silver, carbon nanotubes, and other electrically conductive metals, which cures into an electrically conductive silicone adhesive with a volume resistivity below 0.001 Ohm-centimeter without exceeding a total metal concentration of 72 weight percent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the concentration of silver particles is reduced below 70 wt%, then the cost of the ECA is reduced, but the volume resistivity increases above 0.001 Ohm-centimeter
Solution Approach 1:
The patent combines silver particles with carbon nanotubes to form a composite conductive network. This composite structure allows the use of lower silver content (50-60 wt% instead of 70 wt%) while maintaining electrical conductivity through the synergistic conductive pathways provided by both silver and carbon nanotubes.
Solution Approach 2:
The patent changes the physical and chemical parameters of the binder matrix by using a silicone-based system with specific crosslinking mechanisms. This modified matrix environment optimizes the dispersion and conductive network formation of metal particles, enabling satisfactory electrical performance at reduced metal concentrations.
2Ease of operation
If ingredients are added to thicken the curable precursor composition, then the rheology is improved for application, but the volume resistivity increases
Solution Approach 1:
The patent modifies the rheological properties by adjusting the silicone binder matrix parameters including viscosity, crosslinking density, and composition ratios. These parameter changes achieve desired flow characteristics and application properties without introducing thickening ingredients that would increase volume resistivity.
3Reliability
If the ECA formulation is optimized for low volume resistivity, then electrical performance is improved, but the flexibility and durability under temperature variations deteriorate
Solution Approach 1:
The silicone-based composite ECA combines the electrical conductivity of metal particles with the thermal stability and flexibility of the silicone matrix. This composite structure maintains electrical performance while providing durability and flexibility under temperature variations through the inherent properties of the silicone binder system.
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 solution allows for flexible, durable electrically conductive silicone adhesives with adjustable rheology and maintained electrical properties, suitable for various electronic applications while reducing the cost of silver content.
Implementation Method 1
The curable silicone composition contains a curable organosiloxane composition, silver, and at least one electrically conductive metal other than silver... while the composition remains curable to an electrically conductive silicone adhesive
Implementation Method 2
a thixotropic index that is adjustable from 3 to 10 measured according to TI Test Method
Implementation Method 3
The ECA binds the components together and facilitates transfer of electric current between them via the ECA during operation of the electrical device
Data Source
AI summary
A curable silicone composition containing a curable organosiloxane composition, silver, and at least one electrically conductive metal other than silver, the curable silicone composition being characterizable by a total silver concentration of from 50 to less than 60 weight percent and a thixotropic index that is adjustable from 3 to 10 measured according to Tl Test Method while the composition remains curable to an electrically conductive silicone adhesive having a volume resistivity of less than 0.001 Ohm-centimeter measured according to Volume Resistivity Test Method without increasing the total concentration of electrically conductive metal in the curable silicone composition to 72 weight percent or higher, the electrically conductive silicone adhesive, an electrical device comprising the electrically conductive silicone adhesive, and a method of manufacturing the electrical device.