Electrochromic Window Bus Bar Seal Integrity via Intermediary Conductor

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Solution Overview

Problem

Conventional dynamic Insulated Glass Unit (IGU) windows face reliability issues due to the breaching of seals by bus bars used for electrical contact, which is one of the highest risk failure modes, as the electrochromic coating is delicate and cannot extend underneath for direct contact, necessitating a seal-breaching solution.

Innovation Solution

The use of a conducting substrate with electrically isolated zones on the transparent substrate, allowing for electrical contact without breaching the seal, by forming bus bars within the sealed volume and using ultrasonic soldering to create a conductive path between the layers, eliminating the need for a bus bar underneath the seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a bus bar is used to provide electrical contact to the electrochromic coating layer, then electrical connection is achieved, but the seal is breached reducing reliability

Engineering Contradiction:

Improveelectrical connectionVSAvoidseal integrity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent introduces an intermediary conductive member that extends through the seal to provide electrical contact. This intermediary element allows the bus bar to connect to the electrochromic coating without the bus bar directly breaching the seal, thereby maintaining seal integrity while achieving electrical connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transitions from a conventional planar bus bar configuration to a three-dimensional structure where the conductive member extends through the seal depth. This dimensional change allows electrical contact to be made from the exterior while the conductive member passes through the seal volume rather than breaching the seal surface.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If the electrochromic coating is kept within the sealed volume for protection, then coating integrity is maintained, but electrical contact becomes difficult

Engineering Contradiction:

Improvecoating protectionVSAvoidelectrical contact

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The conductive member serves as an intermediary that bridges the sealed volume containing the electrochromic coating and the exterior environment. It provides a pathway for electrical contact to reach the coating without requiring the coating itself to extend outside the sealed volume.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the electrical contact function into two parts: the conductive member that extends through the seal and the bus bar that remains outside the sealed volume. This segmentation allows the coating to remain protected within the seal while electrical contact is established through the segmented conductive path.

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If the seal is breached by the bus bar for electrical access, then electrical connection is enabled, but failure risk increases

Engineering Contradiction:

Improveelectrical accessVSAvoidfailure risk

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The conductive member acts as a protective intermediary that allows electrical access without direct bus bar contact with the seal. This intermediary structure isolates the seal from the bus bar, eliminating the harmful effect of seal breaching while maintaining electrical access capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent provides beforehand cushioning by designing the conductive member to absorb and distribute mechanical stresses that would otherwise be transmitted to the seal. This pre-engineered stress distribution prevents seal failure before it can occur during operation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

This approach enhances the reliability of the IGU by preventing seal breaches and improving the electrical operation of the electrochromic stack, reducing the risk of failure modes associated with conventional bus bar methods.

Implementation Method 1

using ultrasonic soldering to create a conductive path between the layers

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentUS7719751B2Electrical contact technique for electrochromic windows

Publication Date: 2010.05.18 VIEW OPERATING CORP

AI summary

A window assembly comprises a first conductive material layer, an electrochromic stack, a second conductive material layer and a seal. The first conductive material layer is formed on a substrate and comprises at least two zones electrically isolated from each other. The electrochromic stack is formed on a first selected zone of the first conductive material layer to overlap an edge of a second selected zone of the first conductive material layer. The second conductive material layer is formed on the electrochromic stack to overlap an edge of the second selected zone. A first bus bar is formed on the second selected zone to be within a sealed volume of the window assembly. A second bus bar is formed on the first selected zone to be outside the seal volume of the window assembly. The seal defines the sealed volume of the window assembly and seals the window assembly.