Floating-Terminal Temperature Sensor for Rapid Thermal Response

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Solution Overview

Problem

Existing temperature sensors for motor stators face challenges in achieving high thermal responsiveness and thermal followability due to the interposition of insulating substrates between heat collecting films and heat-sensitive elements, hindering efficient heat transfer.

Innovation Solution

A temperature sensor design featuring a heat-sensitive element mounted on a conductive floating terminal with direct contact and electrical connections via bonding wires, allowing for efficient heat transfer to the heat-sensitive element while maintaining thermal isolation from lead terminals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a heat collecting film is provided on the contact surface with a measurement target object to efficiently transfer heat, then thermal responsiveness is improved, but thermal followability deteriorates due to the interposition of an insulating substrate between the heat collecting film and the heat-sensitive element

Engineering Contradiction:
Improvethermal responsivenessVSAvoidthermal followability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The temperature sensor is segmented into distinct functional zones: a heat collecting film portion for rapid heat acquisition, an insulating substrate portion for thermal isolation, and a heat-sensitive element portion for precise temperature detection. This segmentation allows each portion to optimize its specific function without compromising the others, achieving both high thermal responsiveness and accurate thermal followability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the temperature sensor are assigned different thermal properties: the heat collecting film has high thermal conductivity for rapid heat transfer, the insulating substrate has low thermal conductivity for heat isolation, and the heat-sensitive element has controlled thermal mass for accurate temperature sensing. This local differentiation of thermal qualities enables simultaneous optimization of responsiveness and measurement accuracy

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If an insulating substrate is interposed between the heat collecting film and the heat-sensitive element to provide structural support, then manufacturing precision is improved, but thermal responsiveness deteriorates due to hindered heat transfer

Engineering Contradiction:
Improvestructural stabilityVSAvoidthermal responsiveness
Core Design Contradiction:
Manufacturing precisionVSSpeed

Solution Approach 1:

The insulating substrate is designed as a thin film structure that provides necessary structural support and positioning while minimizing thermal resistance. The thin film configuration allows heat to pass through more efficiently compared to a thick substrate, thereby maintaining thermal responsiveness while still providing the required structural stability for manufacturing precision

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If the heat-sensitive element is mounted directly on the heat collecting film to improve thermal followability, then thermal responsiveness is improved, but device complexity increases due to additional mounting structures

Engineering Contradiction:
Improvethermal followabilityVSAvoidmounting structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heat-sensitive element is integrated directly onto the heat collecting film in a merged configuration, eliminating the need for separate mounting structures. This integration reduces device complexity while maintaining direct thermal contact between the heat-sensitive element and the heat collecting film, thereby achieving high thermal followability without additional structural complexity

Inventive Principle:
Principle #5Merging (Combining)

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 design enhances thermal responsiveness, enabling accurate and rapid temperature measurement of motor stator coil conductors by efficiently transferring heat to the heat-sensitive element.

Implementation Method 1

the electrode surface on the lower surface is bonded to the floating terminal with a conductive bonding material

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

electrical connection between the electrode surface on the upper surface with the other of the pair of lead terminals are performed by bonding wires

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4628862A1Temperature sensor
Publication Date: 2025.10.08 MITSUBISHI MATERIALS CORP
  • EP4628862A1 patent drawingFigure 1~2
  • EP4628862A1 patent drawingFigure 3~4
  • EP4628862A1 patent drawingFigure 5~6

AI summary

There is provided a temperature sensor capable of highly accurately measuring a temperature with higher thermal responsiveness. A temperature sensor according to the present invention includes a heat-sensitive element 2 having electrode surfaces on an upper surface and a lower surface; a pair of lead terminals 3 electrically connected to the heat-sensitive element; a resin sealing portion 4 that seals the heat-sensitive element and distal end portions of the pair of lead terminals with resin; and a conductive floating terminal 5 that is embedded in the resin sealing portion with at least a surface exposed and is separated apart from the pair of lead terminals, in which the heat-sensitive element is mounted on the floating terminal in a state where the electrode surface on the lower surface is bonded to the floating terminal with a conductive bonding material, and electrical connection between the floating terminal and one of the pair of lead terminals and electrical connection between the electrode surface on the upper surface with the other of the pair of lead terminals are performed by bonding wires.