Rigid-Flexible PCB With Embedded Optical Waveguides
Solution Overview
Problem
Existing rigid-flexible printed circuit boards face challenges in integrating optical waveguides efficiently while maintaining flexibility and minimizing overall height, as conventional methods are limited by the thickness of the flexible circuit board part and the need for reliable, long-lasting connections in applications like mobile devices.
Innovation Solution
The integration of optoelectronic components in cavities within the printed circuit board, with a structured optical waveguide layer using multi-photon absorption, allowing for a compact and flexible design that maintains thinness and flexibility, and uses an adhesive layer for connection between rigid and flexible parts, enabling three-dimensional optical waveguide structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical waveguides are integrated in conventional rigid printed circuit boards, then data transmission functionality is improved, but overall height and thickness increase
Solution Approach 1:
The patent transitions optical waveguide integration from conventional rigid PCBs to flexible substrates, utilizing the flexibility dimension to achieve compact three-dimensional routing. This allows optical connections to be implemented in space-constrained environments without increasing overall height, as the flexible substrate can be bent and folded to route waveguides through available vertical and lateral spaces.
Solution Approach 2:
The patent employs flexible substrates (thin films) as the base for integrating optoelectronic components and optical waveguides. This flexible film approach enables the optical connection structure to maintain a thin profile while providing the necessary mechanical flexibility for compact packaging and three-dimensional routing, directly addressing the height reduction requirement.
2Adaptability or versatility
If the flexible circuit board part is made thinner to maintain flexibility, then flexibility is improved, but mechanical strength and reliability decrease
Solution Approach 1:
The patent utilizes composite material structures combining flexible substrate materials with integrated optoelectronic components and optical waveguides. This composite approach allows the flexible circuit board part to maintain thinness for flexibility while the integrated components and multi-layer construction provide the necessary mechanical strength and reliability for permanent connections under mechanical stress.
Solution Approach 2:
The patent implements a nested structure where optoelectronic components and optical waveguides are integrated within the flexible substrate layers. This nesting approach allows multiple functional elements to be contained within the thin flexible structure, providing mechanical reinforcement through the multi-layer construction while maintaining overall flexibility and thinness.
3Reliability
If permanent connections are provided for long-lasting mechanical stress, then reliability is improved, but adaptability for temporary connections decreases
Solution Approach 1:
The patent creates a universal connection platform using flexible substrates with integrated optical waveguides that can serve both permanent and temporary connection applications. The flexible nature of the substrate allows the same structure to be used for durable permanent installations while also enabling temporary connections through flexible routing and positioning, achieving multi-functionality across different application scenarios.
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 efficient integration of optical waveguides in rigid-flexible printed circuit boards, ensuring high flexibility and reliability with minimal material usage, suitable for high data transfer rates and diverse applications like mobile devices and optoelectronic backplanes.
Implementation Method 1
The optically active layer, in particular a photopolymerizable layer, is acted on by light, in particular laser radiation, at a wavelength at which the optically active layer activates polymerization only through multi-photon absorption
Implementation Method 2
a photopolymerizable layer, is acted on by light, in particular laser radiation, at a wavelength at which the optically active layer activates polymerization only through multi-photon absorption
Data Source
AI summary
The invention relates to a printed circuit board element (10), comprising at least one flexible printed circuit board part (12) and at least one rigid printed circuit board part (11A, 11C; 34, 35; 37) having a component (17), which is accommodated in a cavity (14) and with a light-emitting or light-receiving part (20) projects over the edge (18) of the cavity (14), wherein the flexible printed circuit board part (12) has a flexible layer (15') made of an optical, photopolymerizable material (15), in which an optical fiber (15) is structured in alignment with the light-emitting or light-receiving part (20) of the optoelectronic component (17) by way of radiation.