Adhesive Bus Bars for Electrochromic Glass Aesthetic Integration

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Solution Overview

Problem

Conventional electrochromic glass windows suffer from aesthetically unpleasing bus bars and scribe lines that are visible in the viewable area, reducing the window's aesthetic appeal and viewable space, despite efforts to obscure or embed them within the primary seal.

Innovation Solution

The use of adhesive bus bars with electrically conductive backings and tinting agents that match the color of the primary sealant or spacer, ensuring they reside under the spacer, thereby blending with the background and remaining invisible from the outside, while maintaining electrical conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional bus bars and scribe lines are used in electrochromic glass windows, then electrical conductivity and structural integrity are maintained, but aesthetic appeal and viewable area are reduced due to visible contrast

Engineering Contradiction:
Improveelectrical conductivityVSAvoidaesthetic appearance
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The bus bar incorporates a tinting agent that matches the color of the primary sealant, allowing the bus bar to blend visually with the surrounding sealant and become substantially invisible from the exterior. This color matching resolves the contradiction by maintaining electrical conductivity while eliminating aesthetic degradation.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The bus bar is embedded within the primary sealant layer, using the sealant as an intermediary medium that conceals the bus bar from external view. This positioning within the sealant structure allows the bus bar to perform its electrical function while being aesthetically camouflaged.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If bus bars are embedded within the primary seal to improve aesthetics, then visual appearance is enhanced, but manufacturing complexity and precision requirements increase

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidmanufacturing process
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The bus bar manufacturing process is merged with the primary sealant application process. The tinted bus bar is applied to the electrochromic device and then the primary sealant is applied over it in a coordinated manner, integrating two functions into a unified manufacturing sequence that reduces overall complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bus bar is prepared in advance with the tinting agent incorporated before being positioned on the electrochromic device. This preliminary preparation of the bus bar with matching color simplifies the subsequent assembly process and reduces the need for complex in-situ adjustments during manufacturing.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If visible bus bars are used, then manufacturing simplicity is maintained, but viewable area and aesthetic quality are compromised

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidviewable area
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

By changing the color of the bus bar through tinting to match the primary sealant, the bus bar becomes visually integrated with the sealant. This allows the bus bar to remain in its simplified positioned role without creating visual distraction, thereby preserving maximum viewable area while maintaining manufacturing simplicity.

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP3887902B1Method of fabricating an electrochromic insulated glass unit comprising an adhesive bus bar
Publication Date: 2025.11.19 VIEW INC
  • EP3887902B1 patent drawingFigure 1A
  • EP3887902B1 patent drawingFigure 1B
  • EP3887902B1 patent drawingFigure 2A~2B

AI summary

Embodiments described include adhesive bus bars for electrochromic or other optical state changing devices. The bus bars are configured to color match and/or provide minimal optical contrast with their surrounding environment in the optical device, provide better adhesion than ink based bus bars, as well as obviate the need to mitigate defects in underlaying layers.