Thermoformable Conductive Inks for Multi-Layer Electronics
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Solution Overview
Problem
The formation of complex thermoformed in-molded electronic devices with multiple layers of graphic inks, conductive circuitry, and insulating layers is challenging due to compatibility issues and material requirements, leading to cracking, delamination, and loss of conductivity during the thermoforming process.
Innovation Solution
The development of thermoformable conductive inks and coatings that include a polymer resin blend with a conductive metal powder, designed for compatibility and adhesion across layers, allowing for high elongation without cracking and maintaining conductivity, using a combination of vinyl, polyurethane, and polyester resins with energy-curable and solvent-based formulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional conductive inks are used in thermoforming processes, then the printed layers can be applied to substrates, but the layers crack and delaminate during thermoforming due to insufficient flexibility and adhesion
Solution Approach 1:
The patent uses composite material formulations for conductive inks that combine multiple polymer resins (flexible polymers, thermoplastic polymers, and thermosetting polymers) with conductive particles. This composite approach creates a material that simultaneously provides flexibility, adhesion, and conductivity, resolving the contradiction between maintaining layer integrity during thermoforming and ensuring reliable electrical conduction.
Solution Approach 2:
The patent modifies the chemical and physical parameters of the ink formulation by incorporating specific ratios of flexible polymers to thermoplastic and thermosetting polymers. This parameter adjustment allows the ink to exhibit both flexibility (to prevent cracking) and strong adhesion (to prevent delamination) during the thermoforming process, while maintaining electrical conductivity through conductive particle incorporation.
2Adaptability or versatility
If multiple layers of graphic inks, conductive circuitry, and insulating layers are formed, then complex electronic devices can be created, but compatibility issues cause cracking, delamination, and loss of conductivity
Solution Approach 1:
The patent achieves homogeneity in the ink formulation by carefully balancing the polymer resin components (flexible polymers, thermoplastic polymers, and thermosetting polymers) to create a unified matrix that provides consistent mechanical properties across all printed layers. This homogeneous composition ensures that multiple layers bond together reliably without delamination while maintaining flexibility to prevent cracking during thermoforming.
Solution Approach 2:
The conductive ink formulation uses a composite material system that integrates conductive particles within a multi-component polymer matrix. This composite structure ensures compatibility with both graphic and insulating layers while maintaining electrical conductivity, enabling the reliable formation of complex multi-layer electronic devices through thermoforming processes.
3Reliability
If conductive inks with high conductivity are used, then low sheet resistance is achieved, but the inks lack flexibility and adhesion required for thermoforming
Solution Approach 1:
The patent resolves this contradiction by creating a composite conductive ink where conductive particles are embedded in a composite polymer matrix consisting of flexible polymers, thermoplastic polymers, and thermosetting polymers. This composite structure allows the ink to achieve low sheet resistance through the conductive particle network while simultaneously providing flexibility and adhesion through the multi-component polymer system.
Solution Approach 2:
The patent applies local quality by creating distinct functional zones within the conductive ink: conductive particles provide localized electrical conductivity pathways, while the flexible polymer matrix provides localized flexibility and adhesion. This spatial differentiation of functions allows the ink to simultaneously achieve low sheet resistance and the mechanical properties needed for thermoforming.
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 high-quality, complex electronic devices with mutually compatible layers that can withstand thermoforming and injection molding without delamination or loss of conductivity, achieving low sheet resistance and flexibility, thus overcoming the limitations of existing technologies.
Implementation Method 1
thermoformable conductive inks and coatings that include a polymer resin blend with a conductive metal powder, designed for compatibility and adhesion across layers, allowing for high elongation without cracking
Implementation Method 2
using a combination of vinyl, polyurethane, and polyester resins with energy-curable and solvent-based formulations
Data Source
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AI summary
Thermoformable inks and coatings, such as conductive inks and coatings, are provided. These inks and coatings can be used in printed electronic thermoformed devices. These conductive inks and coatings are suitable to be used as one or more printed layers of a printed electronic device printed with multiple layers of inks and/or coatings (printed stacked array). Methods of fabricating printed electronic devices using the thermoformable inks and coatings are also provided.