Riveted Circuit Substrate Contact Between Aluminum and Copper

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Solution Overview

Problem

Existing circuit carrier arrangements face electrical contact issues between aluminum-based base layers and copper-based circuit layers, leading to increased costs and reduced robustness, especially in moving devices like vehicles.

Innovation Solution

A rivet-based connection system is used to establish electrical contact between an aluminum base layer and a copper circuit layer, utilizing a force-fit connection with the base layer and a material-fit connection with the circuit layer, facilitated by a dielectric intermediate layer and a rivet with a head that rests on the circuit layer, secured by solder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an aluminum base layer is used in the circuit carrier arrangement, then cost is reduced and thermal dissipation is improved, but electrical contact problems arise between the aluminum base layer and copper circuit layer

Engineering Contradiction:
ImprovecostVSAvoidelectrical contact
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces a rivet as an intermediary component that physically and electrically connects the aluminum base layer and copper circuit layer. The rivet acts as a mediator that bridges the two incompatible metal substrates, enabling reliable electrical contact while allowing the use of cost-effective aluminum for the base layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a rivet connection is implemented between aluminum base layer and copper circuit layer, then electrical contact reliability is improved, but device complexity increases

Engineering Contradiction:
Improveelectrical contactVSAvoidconnection structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the rivet component: it serves as both a mechanical fastener to join the layers and as an electrical conductor to establish electrical contact. This merging of mechanical and electrical functions into a single component reduces overall device complexity compared to using separate fasteners and electrical contacts.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If copper-based IMS are used instead of aluminum-based IMS, then electrical contact is improved, but manufacturing cost increases significantly

Engineering Contradiction:
Improveelectrical contactVSAvoidcost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by using copper only where electrical contact is needed (in the rivet at the connection point) while the bulk of the base layer remains aluminum. This localized use of copper provides the necessary electrical conductivity at the interface without incurring the full cost of a copper-based IMS throughout the entire structure.

Inventive Principle:
Principle #3Local quality

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 enables reliable, cost-effective electrical contact between different metal substrates, enhancing robustness and electromagnetic compatibility, particularly suitable for moving devices.

Implementation Method 1

A force-fit connection is formed between the rivet and the base layer

Methodology Applied
Scientific EffectForce-fit connection: Mechanical Fastener

Implementation Method 2

a material-fit connection is formed between the rivet and the circuit layer... A metallurgical bond is preferably formed between the head and the circuit layer. The material-bonded connection is preferably produced using a solder

Methodology Applied
Scientific EffectSoldering: Soldering

Implementation Method 3

an aluminum base layer and a copper circuit layer, which are separated from each other by a dielectric intermediate layer

Methodology Applied
Scientific EffectDielectric insulation: Dielectric

Data Source

PatentEP3743943B1Circuit substrate arrangement with improved electrical contact
Publication Date: 2026.02.11 ROBERT BOSCH GMBH
  • EP3743943B1 patent drawingFigure 1~2
  • EP3743943B1 patent drawingFigure 3~4

AI summary

The present invention relates to a circuit substrate arrangement comprising a base layer (2) made from aluminium, a circuit layer (3) made from copper, a dielectric layer (4) arranged between the base layer (2) and the circuit layer (3), an opening (5) passing through the base layer (2), the circuit layer (3) and the dielectric layer (4) and an electrical contact (6) between the base layer (2) and the circuit layer (3), wherein the electrical contact (6) comprises a rivet (7), wherein a frictionally connected joint (8) is formed between the rivet (7) and the base layer (2) and wherein an integrally bonded joint (9) is formed between the rivet (7) and the circuit layer (3).