Spray-Coated Contact Element for Low-Resistance Electrical Joints

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current electrical connections between conductors, such as busbars, experience high contact resistance due to constriction and surface contamination resistance, which impairs current transmission.

Innovation Solution

A contact element with an electrically conductive carrier body featuring a spray coating of conductive solid particles distributed over its surface, forming micro-contacts that reduce contact resistance by increasing contact pressure and breaking open contamination layers, while the particles' geometry and distribution optimize current flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional continuous contact surfaces are pressed together, then contact pressure is distributed evenly, but contact resistance increases due to surface contamination and constriction resistance

Engineering Contradiction:
Improvecontact resistanceVSAvoidsurface contamination resistance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The contact surface is segmented into discrete micro-contacts formed by spray-coated particles rather than a continuous surface. These particles create multiple localized contact points (a-spots) that concentrate current flow and penetrate contamination layers, reducing both constriction resistance and surface contamination resistance simultaneously

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact element applies local quality by creating regions of high contact pressure at discrete particle locations rather than uniform distribution. The spray-coated particles generate localized micro-contacts with high density and pressure at specific points, optimizing current transmission pathways while maintaining lower overall contact resistance

Inventive Principle:
Principle #3Local quality

2Reliability

If conductor surfaces are pre-treated or coated to remove oxide layers, then contact resistance decreases, but manufacturing effort and costs increase

Engineering Contradiction:
Improvecontact resistanceVSAvoidmanufacturing effort
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The spray-coated particles are applied to the contact element in advance to perform the function of penetrating and breaking oxide layers on the conductor surface. This preliminary action eliminates the need for separate oxide removal steps such as pre-treatment or coating of conductors, as the particles themselves perform the penetration function during contact establishment

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The contact element with spray-coated particles serves itself by using the particles to automatically penetrate and break oxide layers on the conductor surface during the connection process. The system eliminates the need for external pre-treatment processes, as the particles perform the oxide-layer-breaking function inherently when contact pressure is applied

Inventive Principle:
Principle #25Self-service

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 contact element significantly reduces contact resistance by creating discrete high-pressure micro-contacts and evenly distributing current flow, allowing for efficient electrical connections without pre-treating or coating the conductors, thus saving effort and costs.

Implementation Method 1

the at least one contact surface comprises a spray coating made of electrically conductive solid particles distributed over the at least one contact surface

Methodology Applied
Scientific EffectSpray coating: Spray

Implementation Method 2

electrically conductive solid particles distributed over the at least one contact surface

Methodology Applied
Scientific EffectParticle distribution: Dispersion (of waves)

Implementation Method 3

the electrically conductive solid particles can form micro-contacts (so-called a-spots) establishing contact at discrete locations at which the current transfer takes place

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

the contact pressure there is higher as compared to continuous contact surfaces pressed together using the same normal force. Any contamination layers that may be present can be broken open

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP4366091A1Contact element with a spray coating as well as connection assembly, use of a spray medium and method for manufacturing a contact element
Publication Date: 2024.05.08 TE CONNECTIVITY GERMANY GMBH
  • EP4366091A1 patent drawingFigure 1
  • EP4366091A1 patent drawingFigure 2~3
  • EP4366091A1 patent drawingFigure 4

AI summary

The present invention relates to a contact element (4) comprising an electrically conductive carrier body (10) with at least one contact surface (6, 6a, 6b) for contacting at least one electrical conductor (8, 8a, 8b), wherein the at least one contact surface (6, 6a, 6b) comprises a spray coating (22) made of electrically conductive solid particles (1) distributed over the at least one contact surface (6, 6a, 6b). The presence and distribution of the solid particles (1) lead to a reduction in the contact resistance between the contact element (4) and the at least one conductor (8, 8a, 8b) when the contact element (4) is pressed with the at least one contact surface (6, 6a, 6b) against the at least one conductor (8, 8a, 8b) and the solid particles (1) have there penetrated at least in part into the material of the at least one conductor (8, 8a, 8b). The present invention furthermore relates to a connection assembly (2) with such a contact element (4). The present invention additionally relates to the use of a spray medium (60) as well as to a method for manufacturing such a contact element (4).