MEMS Stator Coil Layout for Miniaturized Three-Phase Motors

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Solution Overview

Problem

Current methods for miniaturizing stator components of three-phase electric motors, particularly for micro-robots and micro-actuators, face challenges in reducing the size of stator coils effectively while maintaining performance.

Innovation Solution

The method involves manufacturing a stator using MEMS technology with semiconductor materials, featuring ferromagnetic cores and conductive strips arranged in a circular path with 60° separation, connected via through vias and protective caps, allowing for miniaturization and efficient current distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If traditional miniaturization methods are used for stator components, then the size of stator coils can be reduced, but the manufacturing complexity and difficulty increase significantly

Engineering Contradiction:
Improvecoil sizeVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical winding processes with a printed circuit board (PCB) fabrication approach. Conductive traces are deposited and patterned on a substrate to form coil windings, eliminating the need for manual or automated wire winding equipment. This substitution of mechanical manufacturing with a deposition-based process significantly reduces manufacturing complexity while achieving miniaturization of the stator coils.

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

Solution Approach 2:

The patent changes the manufacturing parameters from traditional coil winding dimensions to printed circuit trace dimensions. By using standard PCB fabrication techniques with controlled trace widths and spacing, the coil geometry is defined through deposition parameters rather than mechanical winding parameters. This allows precise control of coil size and shape while utilizing well-established, low-complexity manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If stator components are miniaturized for micro-robots, then the motor size is reduced, but the electrical connectivity and current distribution become more difficult to maintain

Engineering Contradiction:
Improvestator sizeVSAvoidelectrical connectivity
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent employs a PCB substrate that serves multiple functions simultaneously: it provides the structural base for the stator, forms the coil windings through conductive traces, provides electrical insulation through the substrate material, and establishes electrical connections through vias and contact pads. This multi-functional integration maintains reliable electrical connectivity while minimizing the overall stator size, as the same structure performs both mechanical support and electrical conduction roles.

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

Solution Approach 2:

The patent transitions from three-dimensional coil windings to two-dimensional printed circuit traces on a flat substrate. This dimensional reduction simplifies the electrical connectivity architecture by eliminating complex winding patterns and interconnections. The conductive traces are planar and can be precisely routed to achieve optimal current distribution, while vias provide vertical connections if needed. This 2D approach maintains electrical reliability while enabling significant miniaturization of the stator component.

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

This approach enables the creation of a compact, high-performance stator for three-phase asynchronous motors, suitable for micro-robots and micro-actuators, by leveraging MEMS technology to reduce coil size and enhance electrical connectivity.

Implementation Method 1

forming, on the third structural layer 37 in a position corresponding to and above a first side of the core region 8, a first plurality of conductive strips 10 parallel to one another and in electrical contact with the plurality of conductive through vias 14

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

forming, on the first structural layer 25, a ferromagnetic core region 8

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 3

covering said core region 8 with a protective dielectric layer 30

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP4304053A1Method of manufacturing a stator for an electric motor, stator, and electric motor
Publication Date: 2024.01.10 STMICROELECTRONICS SRL
  • EP4304053A1 patent drawingFigure 1~2
  • EP4304053A1 patent drawingFigure 3A~3B
  • EP4304053A1 patent drawingFigure 4A~4C

AI summary

A stator (1) for an electric actuator or motor, comprising: a solid body (20; 35); a ferromagnetic core region (8) between the layers of semiconductor material (24, 38), electrically insulated from said layers of semiconductor material (24, 38); a plurality of conductive through vias (14) through the solid body (20; 35); a first plurality of conductive strips (10), which extend parallel to one another above the core (8); and a second plurality of conductive strips (10), which extend parallel to one another above the core and opposite to the first plurality of conductive strips; wherein the first plurality of conductive strips (10), the plurality of conductive through vias (14), and the second plurality of conductive strips (10) form a winding or coil of the stator (1).