Foldable Hinge Support Structure for Flexible PCB Crack Prevention

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Solution Overview

Problem

Foldable electronic devices experience damage or cracks in flexible printed circuit boards due to the hinge mechanism when transitioning between unfolded and folded states.

Innovation Solution

A foldable electronic device design featuring a hinge with plates that support the flexible printed circuit board, maintaining it flat in both unfolded and folded states, and incorporating rigid portions coupled to the housing and plates to distribute stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flexible printed circuit board is disposed across a hinge to enable folding, then the device can transition between unfolded and folded states, but the hinge causes damage or cracks in the flexible printed circuit board during state transitions

Engineering Contradiction:
Improvefolding capabilityVSAvoidcircuit board integrity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A support structure comprising first and second support members is introduced as an intermediary between the hinge and the flexible printed circuit board. These support members extend along the hinge and provide mechanical support to the circuit board during folding operations, preventing direct contact between the hinge and the circuit board that would cause damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The support members are positioned in advance along the hinge path to cushion and protect the flexible printed circuit board from mechanical damage before the actual folding stress is applied. This preemptive protection prevents cracks and damage during the state transition.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If the flexible printed circuit board extends across the hinge without support, then the device structure remains simple, but the circuit board is susceptible to damage and cracks during folding

Engineering Contradiction:
Improvehinge structure simplicityVSAvoidcircuit board durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The support members are designed as thin, flexible structures that can bend and conform to the hinge movement while providing necessary mechanical support. This maintains the overall simplicity of the hinge structure while adding the required protection functionality.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If support structures are added to protect the flexible printed circuit board from hinge damage, then circuit board integrity is improved, but device complexity increases

Engineering Contradiction:
Improvecircuit board protectionVSAvoidhinge assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The support members serve multiple functions: they provide mechanical support to the flexible printed circuit board, guide the folding motion, and distribute stresses during state transitions. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4401535B1Foldable electronic apparatus
Publication Date: 2026.02.11 SAMSUNG ELECTRONICS CO LTD
  • EP4401535B1 patent drawingFigure 1
  • EP4401535B1 patent drawingFigure 2
  • EP4401535B1 patent drawingFigure 3

AI summary

According to an exemplary embodiment of the disclosure, a foldable electronic device includes a foldable housing including a first housing, a second housing, and a hinge configured to interconnect the first housing and the second housing, and a flexible printed circuit board extending across the hinge, wherein the hinge includes a first plate and a second plate, wherein the first plate includes a first end portion including a first curved surface configured to support the flexible printed circuit board when the foldable housing is in a folded state, and wherein the second plate includes a second end portion including a second curved surface configured to support the flexible printed circuit board when the foldable housing is in the folded state.