Flexible Component Layer Interlocking for Fold Fatigue Life

Solution Overview

Problem

Flexible display devices face reduced fatigue life due to increased strain when attached to rigid members, leading to buckling and premature wear, especially during repeated folding or bending cycles.

Innovation Solution

An electronic device design incorporating a flexible component layer with an interlocking device between the flexible layer and a rigid member, featuring a first interlocking component attached to the flexible layer and a second interlocking component attached to the rigid member, which engages to prevent separation perpendicular to the rigid member's surface, allowing smooth bending and reducing strain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the flexible component layer is directly attached to the rigid member, then the attachment strength is improved, but the fatigue life is reduced due to increased strain during folding or bending cycles

Engineering Contradiction:

Improveattachment strengthVSAvoidfatigue life

Core Design Contradiction:

StrengthVSDuration of action of moving object

Solution Approach 1:

The attachment interface is segmented into multiple discrete interlocking components (protrusions and recesses) distributed across the flexible layer and rigid member, rather than a continuous rigid bond. This segmentation allows localized strain distribution and prevents stress concentration that would otherwise reduce fatigue life while maintaining overall attachment strength.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The interlocking device incorporates a flexible intermediate layer or flexible interlocking components that can bend and deform with the flexible component layer during folding cycles. This flexibility accommodates the strain imposed by repeated bending while maintaining the attachment between the flexible layer and rigid member, thereby extending fatigue life without sacrificing attachment strength.

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If the flexible component layer is rigidly fixed to prevent separation, then the attachment reliability is improved, but the flexibility and bending capability are reduced

Engineering Contradiction:

Improveattachment reliabilityVSAvoidbending capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The interlocking device employs dynamic interlocking components that can adapt their engagement state based on the bending condition. During normal operation, the interlocking components maintain secure engagement to prevent separation. During folding or bending, the interlocking components can temporarily disengage or deform to accommodate the flexibility requirement, thus maintaining both reliability and bending capability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

A flexible intermediary layer or mechanism is introduced between the flexible component layer and rigid member. This intermediary acts as a mediator that allows relative movement and bending while preventing complete separation. The intermediary maintains attachment reliability through controlled engagement while preserving the bending capability needed for flexibility.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If traditional attachment methods are used, then the manufacturing simplicity is maintained, but the interface smoothness during folding is reduced leading to buckling and premature wear

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidinterface smoothness

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The attachment interface is segmented into multiple discrete interlocking components (protrusions and recesses) distributed across the flexible layer and rigid member, rather than a continuous rigid bond. This segmentation allows localized strain distribution and prevents stress concentration that would otherwise reduce fatigue life while maintaining overall attachment strength.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The interlocking device incorporates a flexible intermediate layer or flexible interlocking components that can bend and deform with the flexible component layer during folding cycles. This flexibility accommodates the strain imposed by repeated bending while maintaining the attachment between the flexible layer and rigid member, thereby extending fatigue life without sacrificing attachment strength.

Inventive Principle:

Principle #30Flexible shells and thin films

Data Source

PatentUS11116090B2Electronic devices incorporating flexible component layers with interlocking devices

Publication Date: 2021.09.07 3M INNOVATIVE PROPERTIES CO

AI summary

Electronic Devices Incorporating Flexible Component Layers with Interlocking Devices At least some aspects of the present disclosure directs to an electronic device 100 comprising a rigid member 100A, 100B, a flexible component layer 130, and an interlocking device 110A, HOB disposed between the flexible component layer and the rigid member. The flexible component layer has at least two sections when the flexible component layer is flexed. The interlocking device comprises a first interlocking component attached to or integrated with the flexible component layer, and a second interlocking component attached to or integrated with the rigid member configured to engage with the first interlocking component, such that the engagement prevents the separation of the flexible component layer from the rigid member along a direction generally perpendicular to a surface of the rigid member.