Flexible PCB Coil Assembly for Compact Electromagnetic Actuators

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Solution Overview

Problem

Linear electromagnetic actuators have a large footprint due to visible electronic circuits and require additional cables and connectors, increasing complexity and cost.

Innovation Solution

A coil with a flexible printed circuit board wrapped around the electrical winding, integrated with electronic components and encapsulated in resin or plastic, eliminating external enclosures and connectors, and directly soldered connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid printed circuit board with plastic enclosure is used for the electronic circuit, then the circuit is protected and structured, but the overall footprint of the actuator increases

Engineering Contradiction:

Improvecircuit protectionVSAvoidactuator footprint

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent transitions from a planar rigid PCB layout to a three-dimensional flexible circuit board that can be wrapped around the solenoid coil in multiple layers and directions. This dimensional change allows the circuit to occupy the radial and circumferential space around the coil rather than requiring additional lateral space, thereby reducing the actuator's overall footprint while maintaining circuit protection through encapsulation.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The flexible circuit board is wrapped around and integrated with the solenoid coil, with electronic components mounted on the circuit board. The entire assembly is then encapsulated in a single piece of plastic that forms both structural support and protection. This nested arrangement integrates multiple components (coil, circuit, components, enclosure) into a compact unified structure, minimizing the external dimensions of the actuator.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Adaptability or versatility

If additional cables and connectors are used to connect the electronic circuit to the solenoid, then the circuit can be separately housed, but the complexity and cost of implementation increase

Engineering Contradiction:

Improveseparate housing capabilityVSAvoidimplementation complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the electronic circuit, solenoid coil, and connecting conductors into a single integrated assembly. The flexible circuit board is directly wrapped around the coil with conductive traces that make direct contact with the coil terminals, eliminating the need for separate cables and connectors. This integration simplifies the manufacturing process and reduces component count while maintaining the ability to house the entire assembly in a compact single-piece plastic enclosure.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If the electronic circuit is attached to one of the larger sides of the parallelepiped, then the circuit board can be easily mounted, but the size of the printed circuit board is limited by the surface area available

Engineering Contradiction:

Improvecircuit mounting easeVSAvoidcircuit board area

Core Design Contradiction:

Ease of manufactureVSArea of stationary object

Solution Approach 1:

Instead of mounting the circuit board flat against the external surface of the actuator housing, the flexible circuit board is wrapped around the solenoid coil in three dimensions. This allows the circuit to utilize the radial and circumferential surface area of the cylindrical coil, effectively increasing the available mounting area without increasing the external footprint of the actuator. The flexible nature of the circuit board enables it to conform to the curved surface of the coil.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

The solution provides a compact, cost-effective, and simplified implementation with reduced parasitic capacitance and improved noise immunity, enhancing mechanical robustness and insulation.

Implementation Method 1

The use of the flexible circuit wrapped around the electrical winding allows for a compact solution with the electronic components being installed on the flexible circuit and occupying the available space between the flexible circuit itself and the outer casing, thereby reducing parasitic capacitance between the electrical winding and the outer casing

Methodology Applied

Scientific EffectParasitic capacitance reduction: Capacitance

Implementation Method 2

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP4261854A1Coil for an electromagnetic actuator, method for manufacturing such a coil, and electromagnetic actuator comprising such a coil

Publication Date: 2023.10.18 LMP SRL

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AI summary

Coil (100) for an electromagnetic actuator, comprising at least: - a support (1); - an electrical winding (10) comprising a plurality of turns wound around the support (1); characterized in that it further comprises an electronic circuit (20) which comprises a flexible printed circuit board (22) on which there are arranged one or more electronic components (24) and which is wound, at least in part, around said electrical winding (10). The invention further relates to an electromagnetic actuator comprising such a coil.