Direct Metal Microparticle Deposition for Low-Temperature Chip Interconnects

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Solution Overview

Problem

Existing methods for manufacturing and connecting integrated circuit chip modules and radio frequency antennas in the smart card industry are costly, require high temperatures, and do not maintain optimal electrical conductivity, making them unsuitable for secure devices like contactless smart cards and electronic passports.

Innovation Solution

A method involving direct metal deposition at ambient or low temperatures using pure metal microparticles, free of polymer or solvent, through techniques like FPC and LIFT, allowing for direct deposition of conductive surfaces on low-temperature substrates without the need for high-temperature curing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If chemical etching or traditional printing methods are used to produce conductive tracks, then manufacturing cost is reduced, but electrical conductivity deteriorates due to polymer binder and solvent presence

Engineering Contradiction:
Improvemanufacturing costVSAvoidelectrical conductivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention extracts and removes the harmful components (polymer binder and solvent) from the conductive material formulation, using only pure metal microparticles. This extraction resolves the contradiction by eliminating the source of conductivity degradation while maintaining the additive manufacturing approach's cost-effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the fundamental parameters of the conductive material from a composite formulation (metal particles + polymer binder + solvent) to pure metal microparticles. This parameter change eliminates the conductivity-reducing components while preserving the manufacturing advantages of additive methods.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high temperature curing is applied to coalesce metal particles, then electrical conductivity is improved, but substrate integrity deteriorates due to polymer plastic melting

Engineering Contradiction:
Improveelectrical conductivityVSAvoidsubstrate integrity
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention changes the deposition temperature parameter from high temperature (required for traditional ink curing) to ambient or low temperature (below substrate melting point). This parameter change enables substrate integrity preservation while achieving particle coalescence through alternative mechanisms.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the thermal field (high temperature curing) with an alternative mechanism for particle coalescence that does not rely on high temperature. This substitution resolves the contradiction by achieving conductivity improvement without substrate damage.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If more solvent is used in conductive ink formulation, then ease of deposition is improved, but manufacturing complexity increases due to additional drying and temperature control steps

Engineering Contradiction:
Improveease of depositionVSAvoidprocess complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the solvent component from the conductive material formulation, using only pure metal microparticles. This extraction resolves the contradiction by removing the need for solvent-related process steps (drying, viscosity control, temperature management) while maintaining deposition capability.

Inventive Principle:
Principle #2Taking out (Extraction)

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 reduces manufacturing costs, simplifies the process, maintains excellent electrical conductivity, and enables flexible design and production of secure devices like smart cards and electronic passports with improved radiofrequency properties.

Implementation Method 1

The invention relates to a method for manufacturing a device with a secure integrated circuit chip by direct deposition of conductive material, in particular by plasma-coassisted deposition of metal microparticles

Methodology Applied
Scientific EffectPlasma-coassisted deposition: Plasma Enhanced Chemical Vapour Deposition

Implementation Method 2

The invention relates to a method for manufacturing a device with a secure integrated circuit chip by direct deposition of conductive material, in particular by laser-induced forward transfer (LIFT) of metal microparticles

Methodology Applied
Scientific EffectLaser-induced forward transfer: Laser Ablation

Data Source

PatentEP3371826B1Method for manufacturing a device with an integrated circuit chip by direct deposition of conductive material
Publication Date: 2025.07.23 THALES DIS FRANCE SA
  • EP3371826B1 patent drawingFigure 1~2
  • EP3371826B1 patent drawingFigure 3
  • EP3371826B1 patent drawingFigure 4~6

AI summary

The invention relates to a method for manufacturing a device (1) with a secure integrated-circuit chip, said device having an insulating substrate (14, 24, 24R), electrically conductive surfaces (23, 33, 43, 53, 63) on the substrate, which surfaces are connected or coupled to said electronic chip (30), said electrically conductive surfaces being produced by a step of depositing or transferring conductive material; the method is characterised in that said step of depositing or transferring conductive material is carried out by a technique of directly depositing metal microparticles, which are free of polymer or solvent, onto the substrate, said deposit being obtained by coalescence of the microparticles forming at least one or more uniform cohesive layers that rest directly in contact with the substrate. The invention also relates to the device obtained.