Flexible Substrate Bending for Reduced Bezel and Wire Protection

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Solution Overview

Problem

The challenge is to minimize the bezel area of a portable electronic device while ensuring that wiring units and flexible printed circuit boards (FPCBs) are adequately covered, as existing methods using bent FPCBs can lead to instability and circuit wire cracks.

Innovation Solution

A second flexible substrate is bent to reduce the bezel area, covering wires on this substrate, and a protection member is used to prevent cracks and stabilize the bent area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If the bezel area is made small to achieve a large screen on a small sized portable electronic device, then the screen-to-body ratio is improved, but the wiring units and FPCBs cannot be adequately covered and protected

Engineering Contradiction:
Improvescreen-to-body ratioVSAvoidcoverage and protection of wiring units and FPCBs
Core Design Contradiction:
Area of moving objectVSReliability

Solution Approach 1:

The FPCB is bent into a three-dimensional configuration, extending from the display assembly into the housing. This spatial reconfiguration allows the FPCB to connect components while staying within the reduced bezel area, eliminating the need for a large bezel to accommodate flat wiring.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The FPCB is formed with a bent shape featuring a bending line, creating a curved path that allows the circuit board to navigate around the display assembly and connect to components in the housing without requiring additional lateral space.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Area of stationary object

If the FPCB is bent to reduce the bezel area, then the bezel size is reduced, but the bended part becomes unstable and may generate cracks on circuit wires

Engineering Contradiction:
Improvebezel area sizeVSAvoidstability of bended FPCB part
Core Design Contradiction:
Area of stationary objectVSStability of the object's composition

Solution Approach 1:

A protection film is applied to the FPCB before bending, and a protection member is positioned at the bending line location in advance. These protective elements are pre-installed to prevent damage during the bending process and subsequent handling.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The protection film and protection member serve as cushioning elements that absorb stress and prevent crack formation at the bending line. The protection member specifically targets the vulnerable bending area to prevent harmful effects before they occur.

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

3Area of stationary object

If the FPCB is bent to relocate the control IC under the display, then the bezel area is reduced, but the process handling becomes difficult and crack risk increases

Engineering Contradiction:
Improvebezel areaVSAvoidprocess handling during bending
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The protection film is attached to the FPCB and the protection member is positioned at the bending line before the bending operation. This preliminary protection setup makes the bending process easier to handle by preventing instability and crack formation during manufacturing.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3678116B1Display including bending area and electronic device comprising same
Publication Date: 2023.03.15 SAMSUNG ELECTRONICS CO LTD
  • EP3678116B1 patent drawingFigure 1
  • EP3678116B1 patent drawingFigure 2A~2B
  • EP3678116B1 patent drawingFigure 3

AI summary

A display according to various embodiments of the present invention may comprise: a touchscreen panel; a display panel disposed under the touchscreen panel and including a first flexible substrate; a drive circuit for driving the touchscreen panel or the display panel; and a second flexible substrate extending outward from the touchscreen panel in a partial layer of the touchscreen panel, wherein the second flexible substrate comprises: a drive circuit area in which the drive circuit is disposed; one or more first wirings connected to the drive circuit and the touchscreen panel; and a bending area which is bent with respect to the touchscreen panel. Various other embodiments may also be possible.