3D Circuit Carrier via Stereolithography and Laser Structuring

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Solution Overview

Problem

Current manufacturing methods for three-dimensional circuit carriers, particularly using MID technology, are limited by high costs and inflexibility, making them unsuitable for small series and individualized products, as they require complex injection molding tools and are not adaptable for applications like IoT devices and Retrofitting.

Innovation Solution

Combining stereolithography with laser direct structuring and electroless electroplating, using a UV-curing photopolymer with IR-sensitive additives to create three-dimensional circuit carriers that can be selectively metallized, allowing for the production of complex components with reduced tooling costs and increased flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If injection molding process is used for manufacturing circuit carriers, then manufacturing precision and reliability are improved, but device complexity and manufacturing cost increase due to complex injection molding tools

Engineering Contradiction:
Improvecircuit carrier manufacturing precisionVSAvoidinjection molding tool complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical injection molding process with a photopolymerization-based stereolithography process. Instead of using complex mechanical injection molding tools, the circuit carriers are manufactured by selectively curing photopolymer resin layers using UV light patterns, thereby eliminating the need for complex mechanical tooling while maintaining manufacturing precision.

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

Solution Approach 2:

The patent changes the fundamental manufacturing parameter from mechanical injection of thermoplastic materials to photopolymerization of resin materials. This parameter change enables the use of light-based patterning instead of mechanical molding, reducing device complexity while preserving the ability to manufacture precise circuit carriers.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If injection molding process is used for manufacturing circuit carriers, then manufacturing precision is improved, but adaptability deteriorates for small series and individualized products

Engineering Contradiction:
Improvecircuit carrier manufacturing precisionVSAvoidadaptability for small series production
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

By replacing the mechanical injection molding system with a digital photopolymerization system, the patent enables flexible adaptation to small series and individualized products. The digital control of UV light patterning allows rapid reconfiguration for different circuit carrier designs without requiring new physical tooling, thereby improving adaptability while maintaining manufacturing precision.

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

Solution Approach 2:

The stereolithography system serves multiple functions: it can manufacture circuit carriers for mass production, small series, and individualized products using the same equipment. The digital patterning capability allows the system to adapt to different production volumes and design requirements, providing universal applicability across various manufacturing scenarios.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If stereolithography is used for manufacturing circuit carriers, then adaptability for small series is improved, but manufacturing precision may deteriorate without selective metallization capability

Engineering Contradiction:
Improveadaptability for small series productionVSAvoidcircuit carrier manufacturing precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by incorporating metallizable additives into the photopolymer resin before manufacturing. This preliminary preparation enables subsequent selective metallization of the circuit carrier surface, ensuring that the adaptability benefits of stereolithography do not compromise manufacturing precision, as the metallization capability is pre-integrated into the material structure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses composite materials by combining photopolymer resin with metallizable additives (such as metal particles or compounds). This composite structure allows the circuit carrier to be manufactured with stereolithography's adaptability while the embedded metallizable components enable precise conductor track formation through subsequent metallization processes, thereby maintaining manufacturing precision.

Inventive Principle:
Principle #40Composite materials

4Ease of manufacture

If UV-curing photopolymer with IR-sensitive additives is used, then ease of manufacture is improved for small series, but device complexity increases due to multi-wavelength laser processing

Engineering Contradiction:
Improveease of manufacture for small seriesVSAvoidmulti-wavelength laser processing complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the UV-curing function and IR-sensitive metallization function into a single photopolymer resin material. This merging eliminates the need for separate processing steps or materials, as both the structural formation (via UV curing) and conductor track creation (via IR-induced metallization) are achieved using the same base material, thereby improving ease of manufacture despite the multi-wavelength processing requirement.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The photopolymer resin with IR-sensitive additives serves multiple functions: it provides the structural matrix for the circuit carrier, enables UV-curing for layer-by-layer fabrication, and contains metallizable compounds for subsequent IR-induced conductor track formation. This multi-functionality reduces the need for separate materials and processes, improving ease of manufacture for small series production.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 the cost-effective and high-quality production of complex plastic components with integrated electronic functions, suitable for small batch sizes and individualized products, enhancing functional integration and reliability while reducing assembly steps.

Implementation Method 1

irradiating the base body with light in a first wavelength range in order to harden the plastic mixture to form the base body

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 2

laser activating part of a surface of the base body using a laser, in which laser-activatable compounds in the plastic mixture are activated

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 3

metallizing the laser-activated part of the surface of the base body

Methodology Applied
Scientific EffectElectroless electroplating: Electroplating

Data Source

PatentEP3709778A1Method for producing a three-dimensional switch holder
Publication Date: 2020.09.16 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP3709778A1 patent drawingFigure 1a~1b
  • EP3709778A1 patent drawingFigure 1c~2
  • EP3709778A1 patent drawingFigure 3

AI summary

Exemplary embodiments relate to a manufacturing process for producing a three-dimensional circuit carrier, a three-dimensional circuit carrier, a computer-implemented method for generating control instructions for a laser, a plastic compound, and the use of the plastic compound. The manufacturing process comprises producing a base body of the three-dimensional circuit carrier using a stereolithographic manufacturing process. The base body is produced from a plastic compound. The plastic compound comprises a photopolymer and an additive. The production of the base body includes irradiating the base body with light in a first wavelength range to cure the plastic compound into the base body.The additive is designed to enable laser structuring by irradiation with a laser in a second wavelength range, thereby activating laser-activated compounds in the polymer mixture. This second wavelength range differs from the first. The manufacturing process further comprises the fabrication of one or more conductor structures on the substrate by laser-activating a portion of the substrate's surface with a laser, and metallization of the laser-activated portion of the substrate's surface. The metallization forms the one or more conductor structures.