Flexible Substrate Routing Angles for Curl Prevention

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Solution Overview

Problem

Flexible electronic devices often curl and deform due to unmatched stresses on opposite sides of the substrate during the fabrication process, leading to instability when removed from a rigid carrier.

Innovation Solution

The flexible electronic device incorporates first signal lines and transmission lines with a specific included angle between 10° and 80°, along with through holes and conductive structures, to distribute stress evenly and prevent curling and deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the flexible substrate is temporarily adhered to a rigid carrier during fabrication, then subsequent element fabrication processes can be performed, but the flexible substrate may be easily curled and deformed when removed from the rigid carrier due to unmatched stresses

Engineering Contradiction:

Improvefabrication processVSAvoidsubstrate stability

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent applies asymmetry by arranging transmission lines and signal lines at specific asymmetric angles (10° to 80°) relative to each other. This asymmetric angular configuration creates balanced stress distribution across the flexible substrate, preventing curling and deformation while maintaining manufacturability through the rigid carrier process

Inventive Principle:

Principle #4Asymmetry

2Device complexity

If transmission lines and signal lines are arranged parallel to each other, then routing is simplified, but stress distribution becomes unbalanced causing curling and deformation

Engineering Contradiction:

Improverouting complexityVSAvoidsubstrate stability

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The patent introduces asymmetric angular arrangement between transmission lines and signal lines (10° to 80° angle), replacing the simple parallel configuration. This asymmetric design balances the stress on both sides of the flexible substrate, preventing curling while maintaining reasonable routing complexity

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent changes the geometric parameter (angle) between transmission lines and signal lines from 0° (parallel) to a range of 10° to 80°. This parameter modification optimizes stress distribution across the substrate, eliminating curling and deformation issues

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11500433B2Flexible electronic device

Publication Date: 2022.11.15 AU OPTRONICS CORP

AI summary

A flexible electronic device including a flexible substrate, a plurality of first signal lines, a plurality of first transmission lines, a plurality of first through holes, and a plurality of first conductive structures is provided. The flexible substrate has a first surface and a second surface opposite to the first surface. The first signal lines are located on the first surface and have a first extending direction. The first transmission lines are located on the second surface and have a second extending direction. A first included angle is provided between the first extending direction and the second extending direction. An angle of the first included angle is between 10° and 80°. The first through holes penetrate through the flexible substrate. The first conductive structures are located in the first through holes and are electrically connected to the first signal lines and the first transmission lines.