Stacked Flexible Circuit Members for Low-Height Electronics

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Solution Overview

Problem

Existing devices comprising stacked circuit members tend to have a large height due to the inclusion of multiple circuit members, which limits their compactness and practical applications, especially in wearable devices.

Innovation Solution

The device comprises stacked circuit members with integrated-electrode portions formed on flexible boards, allowing each member to be thinner and reducing the overall height by integrating them in a flexible circuit structure, while maintaining electrical connectivity through a 4x4 grid array of electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple circuit members are stacked to form a device, then the device can integrate more components and functions, but the height of the device increases significantly

Engineering Contradiction:
Improvecomponent integrationVSAvoiddevice height
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The patent combines multiple circuit members (first circuit member, second circuit member, third circuit member) into a single integrated device structure with shared housing and power supply unit. The circuit members are stacked within the same housing volume, merging what would traditionally be separate devices into one compact unit, thereby integrating more components without proportionally increasing height.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a nested arrangement where the third circuit member is positioned within the housing in a manner that utilizes the vertical space efficiently. The power supply unit is nested within the housing and electrically connected to all circuit members, creating a compact nested structure that maximizes component density while controlling overall device height.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of stationary object

If circuit members are made thinner to reduce device height, then the overall device height decreases, but the structural strength and component mounting capability are reduced

Engineering Contradiction:
Improvedevice heightVSAvoidcircuit member structural strength
Core Design Contradiction:
Length of stationary objectVSStrength

Solution Approach 1:

The patent employs a composite structure where each circuit member consists of multiple layers including insulating layers, conductive patterns, and protective coatings. This composite construction allows the circuit members to be thin while maintaining adequate structural strength through the combined properties of different materials working together.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The circuit members are segmented into distinct functional layers (insulating layers, conductive patterns, electrode portions) that can be optimized independently. This segmentation allows each layer to be thin and specialized, yet the cumulative structure provides the necessary strength and functionality.

Inventive Principle:
Principle #1Segmentation

3Reliability

If integrated-electrode portions are used to maintain electrical connectivity between stacked circuit members, then electrical connection is achieved, but the manufacturing complexity increases

Engineering Contradiction:
Improveelectrical connectivityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses homogeneous conductive materials and standardized electrode patterns across all circuit members. The integrated-electrode portions are formed using the same material system and manufacturing processes for each circuit member, which simplifies manufacturing despite the multi-layer complexity by ensuring consistency and interchangeability.

Inventive Principle:
Principle #33Homogeneity

Data Source

PatentEP4236639B1Device comprising stacked circuit members
Publication Date: 2026.01.21 JAPAN AVIATION ELECTRONICS IND LTD
  • EP4236639B1 patent drawingFigure 1~2
  • EP4236639B1 patent drawingFigure 3~4
  • EP4236639B1 patent drawingFigure 5~6

AI summary

A device comprises a first circuit member (40), a second circuit member (50) and a third circuit member (60). The first circuit member comprises a first body (41) for performing the function of the first circuit member and a first flexible board (44) formed with a first integrated-electrode portion (46) including first electrodes (462). The second circuit member comprises a second body (51) for performing the function of the second circuit member and a second flexible board (54) formed with a second integrated-electrode portion (56) including second electrodes (562). The third circuit member comprises a third body (61) for performing the function of the third circuit member and a third flexible board (64) formed with a third integrated-electrode portion (66) including third electrodes (662). The first integrated-electrode portion, the second integrated-electrode portion and the third integrated-electrode portion lie over each other in an upper-lower direction. The first body, second body and the third body are apart from each other when seen along the upper-lower direction.