Stretchable Substrate Hole Layout to Prevent Wiring Disconnection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional stretchable devices experience wiring disconnection due to expansion and contraction, as the wiring near the expansion and contraction prevention guard is subjected to tensile forces that can lead to disconnection.

Innovation Solution

Incorporating a stretchable first substrate with hole portions in non-connection regions and using a connection member to connect overlapping substrates, allowing for controlled expansion and reducing stress on the wiring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If an expansion and contraction prevention guard is used to prevent expansion and contraction of a region including the electrical connection portion, then the stability of the connection region is improved, but the wiring portion near the guard is subjected to tensile forces that can lead to disconnection

Engineering Contradiction:

Improvestability of connection regionVSAvoidreliability of wiring portion

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The substrate is divided into a connection region (overlapping with the second substrate) and a non-connection region (not overlapping). The hole portions are specifically placed in the non-connection region, segmenting the substrate into functional zones with different mechanical properties. This allows the connection region to remain stable while the non-connection region absorbs expansion stresses.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hole portions act as intermediary elements that mediate between the stable connection region and the expanding non-connection region. By providing controlled compliance zones through the hole portions, the patent reduces tensile forces on the wiring portion while maintaining connection stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Area of moving object

If the stretchable circuit body is expanded to increase the area of the device, then the adaptability of the device is improved, but the wiring portion may be disconnected due to tensile forces

Engineering Contradiction:

Improvearea of stretchable circuit bodyVSAvoidreliability of wiring portion

Core Design Contradiction:

Area of moving objectVSReliability

Solution Approach 1:

Different regions of the substrate are given different local qualities: the connection region maintains high structural integrity for stable electrical connections, while the non-connection region incorporates hole portions to provide controlled compliance and stress absorption during expansion.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The hole portions are pre-positioned in the non-connection region to serve as cushioning zones that absorb expansion stresses before they can propagate to the wiring portion. This beforehand cushioning prevents tensile forces from reaching critical levels that would cause disconnection.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Stability of the object's composition

If a rigid structure is used to prevent expansion, then the stability of the connection is improved, but the device cannot be stretched

Engineering Contradiction:

Improvestability of connectionVSAvoidstretchability of device

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The substrate is designed with dynamic characteristics through the inclusion of hole portions in the non-connection region. This allows the structure to transition from a static rigid configuration to a dynamic system that can adapt its shape and area during expansion while maintaining connection stability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The substrate functions as a flexible thin film structure with strategically placed hole portions that enable controlled deformation during expansion. The flexible nature of the substrate combined with the compliant zones created by hole portions allows the device to stretch while preserving electrical connections.

Inventive Principle:

Principle #30Flexible shells and thin films

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

Prevents wiring disconnection by absorbing expansion in the vicinity of the hole portions, thereby enhancing the durability and reliability of the stretchable device.

Implementation Method 1

the stretchable first substrate has a first hole portion in at least one of the first main surface and the second main surface in the non-connection region... absorbing expansion in the vicinity of the hole portions

Methodology Applied

Scientific EffectStress concentration reduction:

Data Source

PatentUS12526915B2Stretchable device

Publication Date: 2026.01.13 MURATA MFG CO LTD

AI summary

A stretchable device that includes: a stretchable first substrate having a first main surface and a second main surface facing each other and extending in a first direction; a stretchable first wiring on the first main surface and extending along the first main surface; a second substrate that has a third main surface and a fourth main surface facing each other; and a second wiring on the third main surface and extending along the third main surface. The first substrate includes a connection region overlapping the second substrate and a non-connection region not overlapping the second substrate when viewed from a direction orthogonal to the first main surface, the stretchable first substrate and the second substrate are connected in the connection region, and the stretchable first substrate has a first hole portion in at least one of the first main surface and the second main surface in the non-connection region.