Printed Electronics Fabrication via Substrate Thermal Shrinkage

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Solution Overview

Problem

Conventional direct-write technologies face challenges in producing printed electrical and optical components with properties equivalent to bulk materials due to residual porosity and organic additives, which limits conductivity and practicality for industrial production.

Innovation Solution

The method involves printing electrically conductive or insulating materials on a substrate that is stretched and then shrunk by applying heat, using heat-shrinkable materials like polystyrene to consolidate ink particles, reducing porosity and increasing density, thereby enhancing conductivity and reducing component size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If extended sintering times at high temperatures are used to reduce porosity and increase density, then material properties improve, but productivity decreases and substrate selection is limited

Engineering Contradiction:
Improvematerial propertiesVSAvoidindustrial production efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention changes the processing parameters by using lower temperatures (below 200°C) combined with stretching and shrinking operations, replacing the conventional high-temperature extended sintering process. This parameter change achieves comparable or superior material properties while dramatically reducing processing time from hours to minutes, thereby resolving the contradiction between reliability improvement and productivity maintenance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies preliminary stretching to the substrate before printing, which pre-configures the substrate to undergo controlled shrinkage during the printing process. This preliminary action enables the ink particles to be naturally consolidated into dense structures without requiring extended high-temperature sintering, thus improving productivity while maintaining material properties.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If conventional direct-write printing is used, then manufacturing simplicity is maintained, but printed component conductivity is substantially less than bulk material

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidelectrical conductivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The substrate is pre-stretched before printing, creating a controlled state that enables subsequent shrinkage to consolidate ink particles. This preliminary action transforms the simple printing process into one that naturally produces dense, high-conductivity traces without complex post-processing, resolving the contradiction between manufacturing simplicity and electrical conductivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention utilizes thermal shrinkage of the pre-stretched substrate to compress and consolidate the printed ink particles. The substrate's thermal response (shrinking upon heating) is harnessed to increase ink particle density and eliminate porosity, thereby achieving bulk-material-equivalent conductivity while maintaining ease of manufacture through a single integrated process.

Inventive Principle:
Principle #37Thermal expansion

3Reliability

If high-temperature sintering is applied to improve conductivity, then porosity is reduced, but organic additives remain and substrate choice is limited

Engineering Contradiction:
ImproveconductivityVSAvoidsubstrate selection
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention fundamentally changes the processing parameters from high-temperature sintering (>300°C) to low-temperature stretching and shrinking (<200°C). This parameter change enables the use of temperature-sensitive substrates such as plastics and polymers that would decompose at high temperatures, thereby expanding substrate selection while achieving comparable conductivity improvement through mechanical consolidation rather than thermal sintering.

Inventive Principle:
Principle #35Parameter changes

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 results in higher density, more conductive, and smaller-sized printed components with improved durability, enabling the fabrication of more devices per unit area with superior performance compared to conventional methods.

Implementation Method 1

shrinking the substrate to a target size. The step of shrinking includes stretching the substrate during printing by an applied potential or tension and releasing the potential or tension force when printing is completed... The step of shrinking can include heating the substrate at a predetermined temperature based on properties of the substrate

Methodology Applied
Scientific EffectThermal shrinkage: Thermal Contraction

Implementation Method 2

The step of shrinking includes stretching the substrate during printing by an applied potential or tension and releasing the potential or tension force when printing is completed

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2978285B1Improved method for fabricating printed electronics
Publication Date: 2019.10.02 HAMILTON SUNDSTRAND CORP
  • EP2978285B1 patent drawingFigure 1
  • EP2978285B1 patent drawingFigure 2a~2c
  • EP2978285B1 patent drawingFigure 3a~3c

AI summary

A method for fabricating printed electronics and optical components includes printing (104) a trace of electrically conductive, semiconductive or insulating material on a substrate and shrinking (106) the substrate to a target size. The material can include an ink, solution, dispersion, powder, slurry, paste or the like. The step of shrinking can include heating the substrate at a predetermined temperature based on properties of the substrate. The step of shrinking can also include heating the substrate for a predetermined duration based on properties of the substrate. The step of shrinking can also include releasing an external electrical potential used to stretch the substrate during printing. For example, the substrate may decrease in area by at least fifty percent during heating.