Printable Electronics Adhesive Layer for Low-Temperature Circuit Fusing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current printed electronics face challenges in creating low-cost, highly conductive circuits and ensuring strong adhesion to various substrates without compromising electrical and thermal performance, particularly due to limitations in temperature and adhesion issues with flexible materials.
Innovation Solution
A method involving the application of an adhesive layer followed by a conductive metal layer, where the conductive metal particles fuse and the adhesive cures at temperatures below 200°C, allowing for strong adhesion and high conductivity without incorporating adhesives into the bulk structure, using a circuit-printing device with separate heads for each layer and optional curing agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal inks are used to create conductive circuits, then electrical conductivity is improved, but processing temperature must be increased to 300°C for 30-60 min to fuse metal particles
Solution Approach 1:
The patent changes the processing temperature parameter from 300°C to below 200°C by using a two-layer system where an adhesive layer is applied first, then a conductive metal layer is applied over it. The adhesive layer acts as a flux that enables metal particle fusion at lower temperatures, thus improving electrical conductivity while reducing processing temperature requirements.
Solution Approach 2:
The adhesive layer serves as an intermediary substance between the substrate and the conductive metal layer. This intermediary enables the metal particles to fuse at lower temperatures by providing a chemical environment that facilitates bonding, thereby resolving the contradiction between achieving high conductivity and maintaining low processing temperature.
2Strength
If adhesive layers are incorporated into the bulk structure to improve adhesion, then adhesion strength is improved, but electrical and thermal performance deteriorates
Solution Approach 1:
The patent segments the adhesive function from the bulk conductive structure by creating a thin adhesive layer at the interface between the substrate and the conductive metal layer. This segmentation allows the adhesive to provide strong bonding while the bulk metal layer maintains its electrical and thermal performance, as the adhesive is confined to a thin interfacial region rather than being distributed throughout the conductive path.
Solution Approach 2:
The adhesive is placed locally at the interface region where adhesion is needed, rather than being incorporated into the bulk conductive structure. This local placement ensures that the adhesive's bonding function is fulfilled while minimizing its impact on the electrical and thermal properties of the conductive circuit.
3Reliability
If high-temperature processing is used to fuse metal particles, then electrical conductivity is improved, but substrate deformation increases
Solution Approach 1:
The patent changes the processing temperature parameter from high temperature (300°C) to low temperature (below 200°C) by using the adhesive layer as a flux. This temperature reduction enables metal particle fusion and circuit formation while preventing substrate deformation, thus resolving the contradiction between achieving good electrical conductivity and maintaining substrate shape integrity.
4Ease of manufacture
If conventional printing processes are used to create circuits, then manufacturing cost is reduced, but resolution and throughput are limited
Solution Approach 1:
The patent uses a composite material system consisting of an adhesive layer and a conductive metal layer. This composite approach enables the use of conventional printing processes at low cost while achieving high resolution, because the adhesive layer provides a forgiving matrix that allows for precise metal particle placement and fusion even with standard printing techniques.
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 the creation of highly conductive circuits with strong adhesion to a wide range of substrates, maintaining near-bulk material performance and flexibility, while avoiding the need for high-temperature processing and reducing substrate deformation.
Implementation Method 1
exposing the first layer and the second layer to a temperature for a duration of time to (1) fuse the particles of the conductive metal together
Implementation Method 2
cure the adhesive of the second layer
Data Source
AI summary
A circuit assembly can be made by adhering a conductive element to a substrate with an adhesive. A first layer including an adhesive can be applied over at least a portion of a surface of the substrate. A second layer including a conductive metal can be applied over at least a portion of the first layer. The first layer and the second layer can be exposed to a temperature for a duration of time to (1) fuse the conductive metal together in at least a portion of the first layer and (2) cure the adhesive of the second layer. The fusing can be substantially complete before the curing is substantially complete to enhance bonding of the adhesive to the fused conductive metal.