Waveform Substrate Scaffold for Stretchable Circuit Boards

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The development of stretchable electronics is limited by the brittleness of inorganic thin film dielectrics and semiconductors, which crack under mechanical deformation, and existing fabrication methods often result in preloaded bend stress and stress concentration in reversibly deformable circuit boards.

Innovation Solution

A substrate scaffold structure with a predefined waveform topography is used to facilitate the deposition of thin film layers, allowing for operational reversible deformation by controlling stress and strain locations, and enabling the use of roll-to-roll manufacturing processes while maintaining electronic components in a neutral stress state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If inorganic thin film dielectrics and semiconductors are used in stretchable electronics, then electronic functionality is achieved, but the materials crack under mechanical deformation due to brittleness

Engineering Contradiction:
Improvemechanical durabilityVSAvoidbrittleness resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The substrate is designed with a waveform topography that segments the structure into repeating wave patterns. This segmentation allows the substrate to deform elastically under stress by expanding and contracting the wave regions, preventing crack propagation in the thin film layers while maintaining electronic functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The substrate employs a waveform (curved) topography instead of a flat surface. The curved wave structure enables the substrate to accommodate mechanical deformation through geometric transformation, allowing stretchable electronics to bend and flex without causing stress concentration that would lead to material failure.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of manufacture

If conventional fabrication methods are used for deformable circuit boards, then manufacturing is simplified, but preloaded bend stress and stress concentration occur in the circuit board

Engineering Contradiction:
Improvefabrication simplicityVSAvoidpreloaded bend stress
Core Design Contradiction:
Ease of manufactureVSStress or pressure

Solution Approach 1:

The waveform topography is pre-defined during substrate fabrication before the thin film layers are deposited. This preliminary structuring ensures that when the circuit board is assembled and operated, the stress is evenly distributed across the wave patterns rather than concentrating at specific points, eliminating preloaded bend stress while maintaining ease of manufacturing through standard processes.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a substrate scaffold structure with waveform topography is used, then reversible deformation is facilitated and stress is controlled, but additional fabrication steps are required

Engineering Contradiction:
Improvereversible deformation capabilityVSAvoidfabrication process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fabrication process is segmented into distinct stages: substrate preparation with waveform topography, thin film deposition, and final assembly. This segmentation allows each step to be optimized independently while maintaining overall process manageability, enabling reversible deformation capability without excessive complexity.

Inventive Principle:
Principle #1Segmentation

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 approach allows for the creation of reversibly deformable circuit boards that can accommodate mechanical deformation without preloaded stress, reducing the risk of damage to electronic components and enabling efficient, large-scale manufacturing.

Implementation Method 1

The substrate scaffold structure comprises a predefined waveform topography to facilitate deposition of one or more scaffold-conforming thin film layers for use in forming electronic circuit elements of a reversibly deformable circuit board

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

heating the substrate to cure the ink droplets

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3087811B1A substrate scaffold structure and associated apparatus and methods
Publication Date: 2024.08.21 NOKIA TECHNOLOGIES OY
  • EP3087811B1 patent drawingFigure 1~3(c)
  • EP3087811B1 patent drawingFigure 4~6C
  • EP3087811B1 patent drawingFigure 7~8B

AI summary

A method comprising forming a substrate scaffold structure for use in the fabrication of a reversibly deformable circuit board, the substrate scaffold structure comprising a predefined waveform topography onto which one or more scaffold-conforming thin film layers can be deposited for use in forming electronic circuit elements of the reversibly deformable circuit board, the waveform topography of the substrate scaffold structure predefined to facilitate operational reversible deformation of the circuit board.