Curable Conductive Joint Composition for Low-Resistance Busbar Connections

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for joining metallic electrical conductors, such as busbars, face challenges in reducing electrical resistance due to naturally occurring oxides and require costly and environmentally challenging processes like plating, while grease-like compositions are unreliable and limited in application.

Innovation Solution

A curable electrical joint composition comprising electrically conductive metals and a curable polymer, which forms a durable seal to reduce electrical resistance and prevent oxidation, using a composition that can be applied without plating and is curable at room temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If nickel, copper, silver, or tin plating is applied to reduce electrical resistance, then conductivity is improved, but manufacturing cost increases and environmental harm worsens

Engineering Contradiction:
Improveelectrical conductivityVSAvoidmanufacturing cost and environmental impact
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, environmentally harmful plating materials (nickel, copper, silver, tin) with a disposable, cost-effective alternative: a curable electrical joint composition containing conductive metal particles suspended in a polymer matrix. This composition is applied as a coating that cures in place, eliminating the need for costly plating processes while maintaining electrical conductivity. The composition can be easily applied and cured, making it a practical disposable solution that replaces permanent plating processes.

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

Solution Approach 2:

The patent employs a composite material system consisting of conductive metal particles (such as aluminum, copper, or silver particles) dispersed within a curable polymer matrix (such as epoxy or polyester resin). This composite structure combines the electrical conductivity of metal particles with the adhesive and protective properties of the polymer matrix, creating a material that provides both electrical connection and environmental protection without requiring traditional plating processes.

Inventive Principle:
Principle #40Composite materials

2Reliability

If preload from steel bolt or stud is increased to create intimate contact, then electrical resistance decreases, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveelectrical resistanceVSAvoidfastening system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary material—the curable electrical joint composition—that facilitates electrical contact between metal surfaces without requiring extreme preload forces. This composition contains conductive metal particles that bridge the gap between surfaces, allowing electrical current to flow through the composition rather than relying solely on direct metal-to-metal contact. The intermediary layer compensates for surface irregularities and oxide layers, reducing the need for high clamp loads while achieving low electrical resistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The curable electrical joint composition acts as a composite intermediary layer between metal surfaces, combining conductive metal particles with a polymer matrix. This composite structure provides both mechanical compliance (allowing it to conform to surface irregularities under moderate pressure) and electrical conductivity (through the metal particle network). The result is a fastening system that achieves low electrical resistance with simpler, lower-preload bolts rather than requiring complex high-preload fastening systems.

Inventive Principle:
Principle #40Composite materials

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 composition effectively reduces electrical resistance and prevents oxidation, offering superior adhesion and durability under harsh conditions, allowing for efficient detection of manufacturing defects and reducing material wastage.

Implementation Method 1

a curable electrical joint composition... which forms a durable seal... and is curable at room temperature

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Implementation Method 2

at least one electrically conductive metal selected from the group consisting of zinc, tin, cadmium, nickel, platinum, gold, silver, copper, aluminum, palladium, rhodium, stainless steel and alloys thereof

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4460840B1Curable electrical joint composition
Publication Date: 2026.03.04 TESLA INC
  • EP4460840B1 patent drawingFigure 1
  • EP4460840B1 patent drawingFigure 2A~2B
  • EP4460840B1 patent drawingFigure 3

AI summary

Provided herein is a. curable electrical joint composition for metallic electrical conductors, and methods of using the same. The curable electrical joint composition includes at least one electrically conductive metal and at least one curable polymer.