PCB Thermal Path Layout for Accurate Power Connector Temperature Sensing

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Solution Overview

Problem

Accurately and reliably measuring the temperature of power contacts in motor vehicle connectors is challenging due to heat isolation from other electrical circuits, particularly at high current levels like 125, 200, or 500 amperes, which can lead to overheating.

Innovation Solution

A printed circuit board with a dielectric support and multiple metal layers, featuring thermal conduction lands and a temperature sensor, allows heat to be efficiently conveyed along two paths to minimize temperature differences and improve measurement accuracy, with optional features for enhanced accuracy and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single thermal conduction path is used, then the structure is simpler, but the temperature measurement accuracy is insufficient

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidthermal conduction path structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The thermal conduction path is segmented into two separate paths: a first thermal conduction path through the first metal layer and a second thermal conduction path through the second metal layer. Both paths converge at the temperature sensor, allowing heat from the contact to be conducted along multiple routes simultaneously. This segmentation improves temperature measurement accuracy by providing redundant thermal pathways while maintaining a manageable structural complexity through the layered PCB design.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the temperature sensor is placed close to the contact, then the measurement accuracy improves, but the isolation from other electrical circuits becomes difficult

Engineering Contradiction:
Improvecontact temperature measurement accuracyVSAvoidelectrical isolation
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The dielectric support acts as an intermediary between the contact and the temperature sensor. The sensor is mounted on the dielectric support rather than directly on the contact, providing electrical isolation while maintaining thermal coupling through the thermal conduction paths formed by the metal layers. This intermediary structure allows the sensor to be positioned close to the contact for accurate measurement while the dielectric material ensures reliable electrical isolation from other circuits.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If high current flows through the contact, then the power transmission capability is improved, but the heat generation and overheating risk increase

Engineering Contradiction:
Improvepower transmission capabilityVSAvoidcontact temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The temperature sensor provides continuous feedback on the contact temperature to the control system. When the sensor detects that the contact temperature exceeds a predetermined threshold, the control system responds by reducing the current flow or interrupting the circuit. This feedback mechanism allows the system to maintain high power transmission capability when needed while automatically preventing overheating by adjusting the current based on real-time temperature measurements from the sensor.

Inventive Principle:
Principle #23Feedback

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 solution significantly enhances the accuracy of contact temperature measurement, enabling effective monitoring and prevention of overheating by ensuring precise heat conduction and isolation from other electrical circuits.

Implementation Method 1

a thermal conduction land is formed in each of the first and second metal layers. The respective thermal conduction lands of the first and second metal layers are electrically connected to one another... This solution significantly enhances the accuracy of contact temperature measurement, enabling effective monitoring and prevention of overheating by ensuring precise heat conduction

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3758454B1Printed circuit board and method for measuring the temperature in a power electrical connector
Publication Date: 2024.12.11 APTIV TECHNOLOGIES AG
  • EP3758454B1 patent drawingFigure 1~2
  • EP3758454B1 patent drawingFigure 3~4
  • EP3758454B1 patent drawingFigure 5~6

AI summary

A printed circuit board (1) is housed in a connector. A temperature sensor (19) is mounted on the printed circuit board between two connection pads (20) located on one of the faces of the printed circuit board. A contact (10) housed in the connector is placed in thermal continuity with two thermal conduction lands (15, 17), one of which (15) is arranged on the same face of the printed circuit board as the connection pads (20) and the other of which (17) is arranged beneath the temperature sensor (19). Each of the connection pads (20) is connected to a temperature measurement circuit.