Foil-Bonded Busbar Contacts Without Plating

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Solution Overview

Problem

Existing methods for plating busbar terminal ends with materials like tin, nickel, or copper are cumbersome and environmentally detrimental, and they complicate the manufacturing process of electrical conductors used in high-current circuits.

Innovation Solution

The use of an electrically conductive foil with different properties than the conductor, metallurgically bonded to the busbar surface via ultrasonic or laser welding, eliminating the need for plating and reducing environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional plating processes (electroless or electroplating) are used to prepare busbar contact surfaces, then electrical conductivity and reliability are improved, but manufacturing complexity increases and environmental contaminants are generated

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the plating process from the manufacturing sequence by applying foil contacts directly to the extruded busbar surface. This removes the complex multi-step plating operation (electroless copper activation, electroplating, rinsing, drying) while maintaining electrical conductivity through the direct metallurgical bond between the foil and aluminum busbar.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the chemical/electrochemical plating system with a mechanical bonding system. The foil contact is mechanically attached to the busbar surface through direct contact and bonding processes (such as friction stir welding or adhesive bonding), substituting the complex electrochemical plating machinery with simpler mechanical bonding equipment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If traditional plating processes are used to prepare busbar contact surfaces, then electrical conductivity is improved, but environmental harm increases due to contaminants

Engineering Contradiction:

Improveelectrical conductivityVSAvoidenvironmental contaminants

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the naturally oxidized aluminum surface, which was previously considered a contaminant or defect requiring removal through plating, into a beneficial bonding surface. The oxide layer on the aluminum busbar is utilized as the bonding interface for the foil contact, eliminating the need for chemical plating processes that generate environmental contaminants while maintaining electrical conductivity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If plating is performed after busbar extrusion, then contact surface preparation is achieved, but processing time and handling complexity increase

Engineering Contradiction:

Improvecontact surface preparationVSAvoidprocessing time

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

The patent applies the foil contact to the busbar surface immediately after extrusion, while the busbar is still in its freshly formed state with a clean, reactive surface. This preliminary action eliminates the need for subsequent plating operations and reduces handling time by performing the contact application at the earliest possible stage in the manufacturing process.

Inventive Principle:

Principle #10Preliminary action

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 method enhances electrical conductivity and reliability while simplifying the manufacturing process and minimizing environmental contaminants.

Implementation Method 1

The electrical contact is metallurgically bonded to the connection surface... using a tool, such as an ultrasonic welding device including a sonotrode

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 2

The electrical contact is metallurgically bonded to the connection surface... using a laser welding device

Methodology Applied

Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentEP4683118A1Electrical conductor with foil electrical contact on planar surface and method of manufacturing same

Publication Date: 2026.01.21 APTIV TECHNOLOGIES AG

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AI summary

This disclosure presents an electrical assembly including an electrical conductor (102) with a planar connection surface (104) and an electrical contact (404) made of an electrically conductive foil (202) with distinct electrical and mechanical characteristics compared to the electrical conductor (102). The electrical contact (404) is positioned on a specific area of the connection surface (104) and is metallurgically bonded to it. This innovative electrical assembly allows for efficient electrical connections with improved performance and reliability due to the unique properties of the electrically conductive foil (202) and the metallurgical bonding process.