Light Control Sheet Electrode Joint Layout for Shock Durability

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Solution Overview

Problem

The existing light control units have a dot-like joint structure formed by solder and lead wire, which is not durable against movement or shock, leading to unreliable connections between the connection members and the transparent electrode layers.

Innovation Solution

A planar joint configuration is implemented between the conductive adhesive layer and the wiring member, with a conductive patterned end joined to the adhesive layer, ensuring contact with a resin part between metal parts, enhancing joint strength and reliability. The connection members are designed to be thinner than the light control layer and electrode sheets, preventing protrusion and improving durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dot-like joint structure formed by solder ball and lead wire is used, then the connection can be established, but the joint durability against movement or shock is poor

Engineering Contradiction:
Improvejoint durabilityVSAvoidjoint strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The connection member is divided into multiple functional layers: conductive adhesive layer, conductive tape layer, and sealing resin layer. This segmentation allows each layer to perform its specific function - the adhesive layer provides bonding, the tape layer provides conductivity and mechanical strength, and the resin layer provides sealing and protection, collectively achieving durable joints

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection member uses composite structure combining different materials: conductive paste (silver paste) for electrical connection, conductive tape (copper tape) for mechanical reinforcement and conductivity, and sealing resin for protection. This composite approach creates a joint that is strong, conductive, and durable against shock and movement

Inventive Principle:
Principle #40Composite materials

2Strength

If the connection member includes thick components (conductive tape and lead wire), then the joint strength is sufficient, but the connection member protrudes from the light control sheet

Engineering Contradiction:
Improvejoint strengthVSAvoidconnection member thickness
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The connection member is designed to extend in the planar direction (lateral dimension) rather than protruding in the thickness direction. The conductive tape and lead wire are arranged to run along the surface of the light control sheet, allowing the joint strength to be achieved through lateral extension rather than vertical thickness

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

Solution Approach 2:

The connection member uses thin conductive tape (copper tape) instead of thick rigid components. The tape provides sufficient mechanical strength and electrical conductivity while maintaining a thin profile that does not protrude from the light control sheet when viewed from the light control region

Inventive Principle:
Principle #30Flexible shells and thin films

3Ease of manufacture

If a dot-like joint structure is used, then the manufacturing process is simple, but the joint reliability under shock and movement is poor

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidjoint reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

Multiple functions are merged into a single integrated connection member structure: the conductive adhesive layer, conductive tape, and sealing resin are combined into one unified component that provides bonding, electrical connection, mechanical strength, and sealing simultaneously. This integrated approach maintains manufacturing simplicity while achieving high joint reliability

Inventive Principle:
Principle #5Merging (Combining)

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

The solution provides a more reliable and durable joint at the connection members, preventing joint failure due to movement or shock, while maintaining a thin profile and ensuring reliable operation in various environmental conditions.

Implementation Method 1

a first conductive adhesive layer 31A joined to a transparent electrode layer 23A

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

Applying a driving voltage across the pair of transparent electrode layers changes alignment of the liquid crystal molecules in the light control layer, thereby changing the light transmittance

Methodology Applied
Scientific EffectLiquid crystal alignment: Liquid Crystals

Data Source

PatentEP3779583B1Light control unit
Publication Date: 2023.12.06 TOPPAN HOLDINGS INC
  • EP3779583B1 patent drawingFigure 1
  • EP3779583B1 patent drawingFigure 2~3
  • EP3779583B1 patent drawingFigure 4~5

AI summary

The light control unit of the present invention includes a light control sheet (20), and a first connection member (30A) configured to connect a first transparent electrode layer (23A) of the light control sheet (20) and a power supply. In plan view of the light control sheet (20), the first transparent electrode layer (23A) includes a first region (SA) contiguous to a light control region (Si), the light control region (Si) being a region where a light control layer (21) is located. The first connection member (30A) includes a first conductive adhesive layer (31A) joined to the first region (SA) and a first wiring member (32A) joined to the first conductive adhesive layer (31A). The first wiring member (32A) includes a wiring layer (34A) and an insulating resin layer (33A), the wiring layer (34A) having a conductive patterned end and being in contact with the first conductive adhesive layer (31A) at the end, the insulating resin layer (33A) supporting the wiring layer (34A).