DC/DC Converter Case Layout for Accurate Temperature Sensing

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Solution Overview

Problem

The accuracy of temperature measurement in electronic devices using a temperature sensor mounted on a substrate is compromised by the substrate's temperature and the ambient atmosphere, leading to decreased precision.

Innovation Solution

An electronic device design featuring a case with a cooling medium, a substrate with a land pattern in contact with the case, and a temperature sensor positioned to face a recessed surface lower than the substrate's support surface, enhancing heat transfer and reducing ambient interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a temperature sensor mounted on the surface of a substrate is used to measure the temperature of the case, then the device structure is simplified and ease of manufacture is improved, but the measurement precision decreases due to interference from substrate temperature and ambient atmosphere

Engineering Contradiction:
Improveease of manufactureVSAvoidmeasurement precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent introduces a heat conduction member (thermal conductor) as an intermediary between the case and the temperature sensor. This mediator efficiently transfers heat from the case to the sensor while isolating the sensor from direct exposure to ambient atmosphere and substrate temperature interference, thereby resolving the contradiction between ease of manufacture and measurement precision

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent positions the temperature sensor on the opposite side of the substrate relative to the case, with the heat conduction member extending through the substrate. This spatial arrangement in another dimension allows the sensor to measure case temperature through the substrate without being directly exposed to ambient conditions, maintaining manufacturing simplicity while improving measurement accuracy

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the temperature sensor is positioned closer to the case to improve measurement accuracy, then measurement precision improves, but the risk of contact between the sensor and the case increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoidreliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The heat conduction member serves as a reliable intermediary that physically separates the temperature sensor from the case while maintaining thermal contact. This mediator allows the sensor to be positioned close to the case for accurate measurement without direct contact, thus improving measurement precision while maintaining system reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The heat conduction member creates a thermal copy or representation of the case temperature at the sensor location. By transferring the thermal state from the case to the sensor through the conduction member, the system achieves accurate temperature measurement without requiring direct sensor-contact with the case, resolving the precision-reliability contradiction

Inventive Principle:
Principle #26Copying

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 improves the accuracy of case temperature measurement by minimizing distance and ambient interference, allowing for precise monitoring of the case temperature and enabling the use of various temperature sensor sizes without contact issues.

Implementation Method 1

a land pattern that is in contact with the case... The heat from the case is transferred to the land pattern

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a case that is cooled by a cooling medium... The temperature of the case and the temperature of the cooling medium correlate with each other

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a case that is cooled by a cooling medium

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3905864B1Electronic device
Publication Date: 2023.12.06 TOYOTA INDUSTRIES CORP
  • EP3905864B1 patent drawingFigure 1~2
  • EP3905864B1 patent drawingFigure 3

AI summary

A DC/DC converter includes a metal case, a power converter accommodated in the case, a substrate, and a temperature sensor mounted on a surface of the substrate. The case includes a bottom wall, a side wall extending from the bottom wall, a boss, and a coupling portion. The coupling portion couples the side wall to the boss. The coupling portion extends from the bottom wall along an axis of the boss and along a surface of the side wall. The temperature sensor is arranged to face the coupling portion.