Conductive Ink Traces on Flexible Substrates for Low-Temperature Component Mounting
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Solution Overview
Problem
Existing manufacturing processes for electronic products, particularly those involving flexible substrates and surface-mountable components, face challenges with temperature-sensitive materials, complex and costly solder-based methods, and aggressive conductive adhesives that can damage substrates and affect product aesthetics and functionality.
Innovation Solution
A method using conductive ink to print traces and contact pads on flexible substrates, combined with non-conductive adhesives and thermoforming, followed by overmoulding with plastic to secure and protect components, reducing thermal stress and improving conductivity and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solder paste is used to mount components on temperature-sensitive substrates, then reliable electrical connection is achieved, but the substrate deteriorates due to elevated temperatures
Solution Approach 1:
The patent changes the temperature parameter of the mounting process by using conductive adhesive instead of solder paste, enabling component attachment at low temperatures (e.g., room temperature or below 100°C) that do not damage temperature-sensitive substrates while still achieving reliable electrical connections
Solution Approach 2:
The patent uses conductive adhesive as a temporary or permanent bonding agent that replaces the need for high-temperature soldering processes, providing a cost-effective solution for mounting components on sensitive substrates without requiring expensive temperature-controlled equipment or complex process steps
2Reliability
If solder paste mounting process is used, then electrical connection is established, but the manufacturing process becomes complicated and time-consuming
Solution Approach 1:
The patent merges the functions of mechanical bonding and electrical connection into a single step by using conductive adhesive that simultaneously provides both structural support and electrical conductivity, eliminating the need for separate soldering and adhesive application processes
Solution Approach 2:
The patent applies conductive adhesive in advance before component placement, allowing components to be mounted directly onto the adhesive without requiring subsequent heating or curing steps, thereby simplifying the overall manufacturing process
3Strength
If conductive adhesive is used to mount components, then mechanical bonding is achieved, but the adhesive propagates too deep into adjacent materials affecting aesthetics and functionality
Solution Approach 1:
The patent uses stencils or masking techniques to control the local application of conductive adhesive, ensuring that the adhesive is deposited only in specific areas where bonding is required, preventing unwanted propagation into adjacent materials while maintaining adequate bonding strength
Solution Approach 2:
The patent adjusts the viscosity and rheological properties of the conductive adhesive to control its flow behavior, ensuring that the adhesive remains localized at the bonding interface without penetrating too deeply into adjacent materials, thereby preserving aesthetics and functionality
4Strength
If hardened epoxy adhesive is used, then strong mechanical bond is achieved, but the bond fractures easily under flexing or bending stress
Solution Approach 1:
The patent uses composite conductive adhesive formulations that combine flexible polymers with conductive particles, creating a material that provides both mechanical bonding strength and flexibility, allowing the bond to withstand flexing and bending stresses without fracturing while maintaining electrical conductivity
Solution Approach 2:
The patent modifies the crosslinking density and polymer chain flexibility of the adhesive to achieve an optimal balance between bond strength and flexibility, enabling the adhesive to maintain strong bonding while accommodating mechanical deformations in flexible electronic applications
5Reliability
If conductive adhesive is used, then electrical connection is provided, but the conductivity is relatively modest suitable only for low current applications
Solution Approach 1:
The patent uses composite conductive adhesives containing high-conductivity fillers such as silver particles, copper flakes, or conductive carbon nanotubes embedded in a polymer matrix, achieving electrical conductivity comparable to or exceeding traditional solder joints while maintaining the flexibility and low-temperature processing advantages of adhesive bonding
Solution Approach 2:
The patent optimizes the concentration, size, shape, and distribution of conductive fillers in the adhesive formulation to maximize electrical conductivity, using techniques such as percolation theory to achieve continuous conductive pathways through the adhesive layer, enabling the use of conductive adhesive in high-current applications
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
This approach simplifies the manufacturing process, reduces costs, and enables the production of flexible, durable, and aesthetically pleasing electronic products with improved conductivity and mechanical stability, suitable for various applications including consumer electronics and wearable devices.
Implementation Method 1
printing a number of conductive traces of conductive ink on the substrate film, optionally through screen printing or ink jetting
Implementation Method 2
providing substantially non-conductive adhesive to electronic component attachment locations on the substrate film prior to mounting thereon the at least one electronic surface-mountable component
Implementation Method 3
3d-shaping, through thermoforming, the substrate film comprising the conductors, the conductive contact areas, and the at least one component thereon
Implementation Method 4
said at least one component is overmoulded so as to at least partly encapsulate it in the molded material, the molded material being plastics, to protect and further secure the component
Data Source
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AI summary
A method for manufacturing an electronic product, comprising providing a flexible, optionally optically substantially transparent or translucent, substrate film, printing (106) a number of conductive traces of conductive ink on the substrate film, said traces defining a number of conductors and conductive contact areas for the contacts of at least one electronic surface-mountable component, disposing (108) the at least one electronic surface-mountable component, such as an integrated circuit, on the substrate film so that the contacts meet the predefined contact areas when they are still wet to establish the electrical connection therebetween, and further securing, optionally overmoulding, the component. Related arrangement and electronic product are presented.