Motor with built-in power conversion device, air conditioner with same motor built-in, water heater, and ventilation blower equipment

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Solution Overview

Problem

Existing motor designs incorporating power converters face challenges with size reduction and increased thickness of mold resin on the counter-stator side due to IC packaging and wiring constraints, leading to inefficiencies in heat dissipation and mechanical connection strength.

Innovation Solution

The motor design mounts semiconductor elements and high-voltage wires on the stator side of the printed board, using a semi-circular arc-shaped printed board and surface-mounting components to reduce board size and resin thickness, while improving mechanical connection strength and heat dissipation through strategic placement of heat spreaders and overheating detecting elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a lead-type IC is used in the power converter circuit, then the mechanical connection strength with the printed board is improved, but the device complexity and manufacturing process complexity increase due to artificial mounting processes

Engineering Contradiction:
Improvemechanical connection strengthVSAvoidmounting process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical lead-type IC mounting system with an electrical connection system using tab extensions that directly contact solder pads on the printed board. This substitution eliminates the need for artificial mounting processes while maintaining electrical connectivity, resolving the contradiction between mechanical strength and manufacturing complexity.

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

2Device complexity

If the IC is mounted on the counter-stator side of the printed board, then the electrical connection is simplified, but the motor size increases due to increased thickness of mold resin required

Engineering Contradiction:
Improvecircuit arrangement simplicityVSAvoidmotor size
Core Design Contradiction:
Device complexityVSVolume of moving object

Solution Approach 1:

The patent inverts the conventional mounting approach by extending tabs from the IC toward the stator side instead of mounting the IC on the counter-stator side. This inversion allows electrical connections to be made through the printed board thickness without requiring additional space on the counter-stator side, thereby reducing motor size while maintaining circuit arrangement simplicity.

Inventive Principle:
Principle #13The other way round (Inversion)

3Volume of moving object

If a surface-mount IC is used to reduce package size, then the device size is reduced, but the mechanical connection strength with the printed board decreases

Engineering Contradiction:
Improvepackage sizeVSAvoidmechanical connection strength
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The patent makes the tab extensions serve multiple functions: they provide electrical connection, mechanical support, and structural reinforcement simultaneously. This multi-functionality allows surface-mount ICs to achieve both size reduction and adequate mechanical connection strength, resolving the contradiction between package size and mechanical strength.

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

4Temperature

If the semiconductor chip is directly mechanically connected to the printed board for heat radiation, then the heat dissipation is improved, but the cost increases due to requirement of metal or sintered base material substrates

Engineering Contradiction:
Improveheat radiation efficiencyVSAvoidsubstrate cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent enables the printed board itself to serve as the heat radiation path by having the semiconductor chip thermally connected to the printed board through the tab extensions and solder joints. This self-service approach eliminates the need for separate metal or sintered base material substrates, achieving both heat dissipation and cost reduction.

Inventive Principle:
Principle #25Self-service

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 configuration allows for a compact motor with enhanced heat management and mechanical strength, reducing the motor's size and weight while maintaining performance, and improving reliability by minimizing the impact of high-voltage wire routing and overheating detection.

Implementation Method 1

a semiconductor module, which converts a voltage of an external power supply into a high-frequency voltage and supplies the high-frequency voltage to a stator

Methodology Applied
Scientific EffectVoltage conversion to high-frequency voltage:

Implementation Method 2

heat of the IC is radiated via a copper foil on a printed board from a heat spreader arranged on an IC package

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2793369B1Motor with built-in power conversion device, air conditioner with same motor built-in, water heater, and ventilation blower equipment
Publication Date: 2017.07.19 MITSUBISHI ELECTRIC CORP
  • EP2793369B1 patent drawingFigure 1
  • EP2793369B1 patent drawingFigure 2~3
  • EP2793369B1 patent drawingFigure 4

AI summary

A motor 61 incorporating a power converter 60 that includes a printed board 1 on which an inverter IC 2, which converts a voltage of an external power supply into a high-frequency voltage and supplies the high-frequency voltage to a stator 3, is mounted, wherein on a surface of the printed board 1 opposed to the stator 3, a high-voltage direct-current input wire 104, which is a copper foil provided on a surface on a stator side, is disposed. One end of the high-voltage direct-current input wire 104 is electrically connected to a high-voltage input line 17 of the external power supply and the other end of the high-voltage direct-current input wire 104 is electrically connected to a high-voltage electrode 11 of the inverter IC 2.