Flexible Circuit Integration of Bumper Acceleration Sensors

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Solution Overview

Problem

The integration of micromechanical acceleration sensors into plastic components, such as bumpers, is hindered by complex mounting processes and limited miniaturization capabilities, leading to increased costs and space requirements.

Innovation Solution

The method involves positioning micromechanical acceleration sensors on a flexible circuit carrier with an integrated conductor track structure, which is then encapsulated with a polymer, allowing for easy alignment and connection, and can be integrated into plastic components using processes like liquid composite molding, without significant additional space or complexity, enabling direct plug connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If micromechanical acceleration sensors are mounted using screw or clip connections on the inside of the bumper, then the sensors can be securely attached to the plastic component, but the assembly process becomes complex and time-consuming

Engineering Contradiction:
Improvesecure attachmentVSAvoidassembly process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the acceleration sensor, flexible circuit carrier with conductor tracks, and mounting structure into an integrated assembly. The sensor is firmly positioned on the flexible circuit carrier which already contains the electrical connection elements, eliminating the need for separate mounting operations and reducing assembly complexity while maintaining secure attachment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The acceleration sensor is pre-positioned and firmly attached to the flexible circuit carrier before integration into the plastic component. This preliminary assembly ensures proper alignment and electrical connection are established in advance, simplifying the final integration step and reducing on-site assembly complexity.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If connectors mounted on a wiring harness are used for electrical contact, then electrical connection can be achieved, but miniaturization is limited and additional space is required

Engineering Contradiction:
Improveelectrical connectionVSAvoidspace requirement
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent uses a flexible circuit carrier with integrated conductor tracks instead of rigid connectors and wiring harnesses. This flexible film structure provides electrical connection while being space-efficient and enabling miniaturization, as it can be conformally integrated into the plastic component without requiring additional volume.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The electrical connection function is merged directly into the flexible circuit carrier that also serves as the mechanical support for the sensor. This integration eliminates the need for separate connectors and wiring harnesses, reducing the overall space requirement while maintaining reliable electrical contact.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If micromechanical acceleration sensors are integrated into plastic components, then space-efficient design is achieved, but alignment and positioning become difficult

Engineering Contradiction:
Improveintegration spaceVSAvoidalignment precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The acceleration sensor is pre-positioned and firmly attached to the flexible circuit carrier in a controlled environment before integration into the plastic component. This preliminary positioning ensures precise alignment is achieved during manufacturing of the sensor-carrier assembly, and this precision is maintained during subsequent integration into the plastic component.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flexible circuit carrier acts as an intermediary structure that provides a stable, pre-aligned platform for the acceleration sensor. This carrier serves as a mediator between the sensor and the plastic component, ensuring precise positioning and alignment are maintained during integration while allowing flexible integration methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 simplifies the mounting process, reduces costs, and allows for space-efficient integration of micromechanical acceleration sensors within plastic components, maintaining the original shape and size of the component while providing protected electrical connections.

Implementation Method 1

The micromechanical acceleration sensor and the flexible circuit carrier are overmolded by at least one polymer

Methodology Applied
Scientific EffectEncapsulation:

Data Source

PatentEP3526611B1Method for arranging a number of micromechanical acceleration sensors on or in a plastic component, and corresponding plastic component
Publication Date: 2024.11.13 ROBERT BOSCH GMBH
  • EP3526611B1 patent drawingFigure 1~2
  • EP3526611B1 patent drawingFigure 3~4
  • EP3526611B1 patent drawingFigure 5a~5b

AI summary

The invention relates to a method for arranging a number of micromechanical acceleration sensors on or in a plastic component, in particular a bumper, and to a corresponding plastic component, in particular a bumper. In step A of the method, the micromechanical acceleration sensor is positioned in or on a flexible circuit carrier in a fixed manner, and the micromechanical acceleration sensor is contacted with an integrated conductor track structure of the flexible circuit carrier. In step B of the method, at least some regions of the micromechanical acceleration sensor and the flexible circuit carrier are arranged on or in the plastic component such that the integrated conductor track structure of the flexible circuit carrier is at least partly exposed.