Electric Switch Brazing Alloy Composition for Direct Wetting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current brazing materials, such as Cu- and Ag-based alloys, exhibit insufficient wetting properties on Ag-metal oxide contact materials, necessitating the use of a costly pure silver backing layer, which increases the expense and complexity of the brazing process for electric switches.

Innovation Solution

A brazing alloy composition comprising elements from groups I (Cd, Mn, Ni, P, Sb, Si, Sn, Ti, and their oxides) and group II (Bi, Mo, Te, W, and oxides of Cu and Zn) is used, which improves wetting behavior and flowability, allowing for the formation of a reliable braze joint without the need for a silver backing layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Cu- and Ag-based brazing materials are used, then the brazing process can be performed, but the wetting properties on Ag-metal oxide contact materials are insufficient

Engineering Contradiction:
Improvewetting propertiesVSAvoidbrazing process complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent modifies the chemical composition parameters of the brazing alloy by incorporating specific elements (Ti, Zr, Hf, and their oxides) in controlled amounts. This compositional parameter change enables the alloy to achieve adequate wetting on Ag-metal oxide contact materials without requiring a silver backing layer, thus improving wetting properties while simplifying the manufacturing process.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a pure silver backing layer is used to improve wetting behavior, then the wetting properties are enhanced, but the cost and process complexity increase

Engineering Contradiction:
Improvewetting behaviorVSAvoidprocess steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the silver backing layer from the traditional brazing structure. By developing a modified brazing alloy composition that can directly wet Ag-metal oxide contact materials, the invention removes the intermediate silver layer, thereby reducing both the number of process steps and the overall cost while maintaining adequate wetting behavior.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of the silver backing layer and the brazing alloy into a single integrated brazing alloy composition. The modified alloy simultaneously provides the wetting enhancement previously achieved by the silver layer and the bonding function of the brazing material, eliminating the need for separate layers and process steps.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If a pure silver backing layer is applied, then sufficient wetting is ensured, but the cost increases

Engineering Contradiction:
ImprovewettingVSAvoidcost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent replaces the expensive pure silver backing layer with a cost-effective modified brazing alloy composition. The new alloy uses more economical base metals (Cu, Ag in controlled amounts) combined with small quantities of active elements (Ti, Zr, Hf, and their oxides) to achieve the necessary wetting performance, significantly reducing material costs while maintaining reliability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 proposed alloy composition enhances the wetting behavior and bonded area fraction in electric switch braze joints, reducing costs and simplifying the brazing process while maintaining the required mechanical and electrical properties.

Implementation Method 1

Upon heating, the brazing alloy 14 melts and joins the carrier material 3 and the silver backing layer 12 to form a braze joint

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

For bonding of the contact to the carrier, various brazing materials can be used

Methodology Applied
Scientific EffectBrazing: Brazing

Implementation Method 3

Most of the commonly used brazing materials, such as Cu- and Ag- based brazing materials, exhibit insufficient wetting properties on Ag-metal oxide

Methodology Applied
Scientific EffectWetting: Wetting

Data Source

PatentEP3481576B1Use of an alloy as a brazing alloy for an electric switch braze joint, an electric switch braze joint, an electric switch and a method of producing an electric switch braze joint
Publication Date: 2024.09.04 ABB (SCHWEIZ) AG
  • EP3481576B1 patent drawingFigure 1~3
  • EP3481576B1 patent drawingFigure 4~5E
  • EP3481576B1 patent drawingFigure 6~8b

AI summary

Embodiments of the present disclosure relate to a use of an alloy as a brazing alloy for an electric switch braze joint, an electric switch braze joint, an electric switch and a method of producing an electric switch braze joint. The alloy composition of said alloy consists of at least one element selected from each of group I and group II listed below, and a balance of impurities, Ag, and at least one of Cu, and Zn. Group I encompasses Cd, Mn, Ni, P, Sb, Si, Sn, Ti, and oxides thereof in a total amount of 0.5 to 45.0 wt.%. Group II encompasses Bi, Mo, Te, W, and oxides thereof, oxides of Cu and Zn in a total amount of 0.1 to 15.0 wt.%.