Connector Terminal Fitting with Neck for Heat Isolation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing connectors with built-in electronic devices face challenges in ensuring connection reliability without damaging the electronic devices due to heat, particularly with the use of lead-free solder which has a higher melting point, leading to voids and reduced reliability under stress conditions like heat shock tests.

Innovation Solution

A connector design featuring a terminal fitting formed by press-working a metal base material into a flat plate with a thinner connecting head and a narrower, resiliently deformable neck portion, accommodated in a synthetic resin housing, which allows for efficient soldering and reduced heat transfer, and a molded portion to cover the electrode and connecting head, thereby preventing void formation and stress concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If heating time for the connecting portion is extended to completely melt lead-free solder, then connection reliability is improved, but the electronic device may be damaged by heat

Engineering Contradiction:
Improveconnection reliabilityVSAvoidheat damage to electronic device
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The terminal fitting is divided into distinct functional portions: a connecting head portion for soldering, a neck portion for heat isolation, and a mounting portion for electronic device attachment. This segmentation allows the connecting head to be heated independently without transferring excessive heat to the electronic device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The neck portion acts as a thermal intermediary between the connecting head portion and the mounting portion. Its narrower cross-section and lower thermal conductivity material create a thermal barrier that isolates the electronic device from heat applied during soldering of the connecting head.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If lead-free solder is used to eliminate lead, then environmental compatibility is improved, but melting difficulty increases leading to void formation

Engineering Contradiction:
Improveenvironmental compatibilityVSAvoidsolder joint quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The connecting head portion is designed with specific local properties: thinner cross-section for rapid heating, larger surface area for heat distribution, and optimized geometry for solder flow. These local quality enhancements ensure complete melting of lead-free solder and proper wetting without voids.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes physical parameters of the connecting head portion including reducing its thickness, increasing its surface area, and optimizing its dimensions relative to the neck portion. These parameter changes enable the connecting head to reach solder melting temperature quickly and maintain it long enough for complete solder melting and void-free joint formation.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the connecting head portion is made thinner for faster heating, then heating efficiency is improved, but structural strength may be reduced

Engineering Contradiction:
Improveheating efficiencyVSAvoidstructural strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The connecting head portion is pre-formed with an optimized thin geometry during press-working of the terminal fitting. This preliminary shaping ensures the correct thickness and dimensions are built-in, providing both rapid heating capability and adequate structural strength for handling and assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The terminal fitting is constructed from metal material that provides both the thermal conductivity needed for rapid heating of the thin connecting head and the mechanical strength required for structural integrity. The metal composition and heat treatment are optimized to achieve both heating efficiency and strength simultaneously.

Inventive Principle:
Principle #40Composite materials

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 design ensures reliable connection between the electronic device and terminal fitting without damaging the device, as it allows for complete solder melting without extended heating times and reduces stress concentrations, enhancing connection reliability and preventing cracks during thermal tests.

Implementation Method 1

the neck portion which is provided on the terminal fitting, narrower than the connecting head portion and resiliently deformable and extends from the connecting head portion

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

pressing solder against the connecting portion to melt the solder for soldering

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP2523269B1Connector and production method therefor
Publication Date: 2015.07.08 SUMITOMO WIRING SYSTEMS LTD
  • EP2523269B1 patent drawingFigure 1
  • EP2523269B1 patent drawingFigure 2~3
  • EP2523269B1 patent drawingFigure 4

AI summary

An object of the present invention is to ensure connection reliability between an electronic device and a terminal fitting without damaging the electronic device by heat. A connector (10) in which a capacitor (20) connected to a ground-side terminal (32) formed by press-working a metal base material in the form of a flat plate is accommodated in a connector housing (50) made of synthetic resin includes a connecting head portion (38) which is provided on the ground-side terminal (32), thinner than the base material and to be connected to a ground-side electrode (21 B) provided on the capacitor (20) by soldering; a neck portion (39) which is provided on the ground-side terminal (32), narrower than the connecting head portion (38) and resiliently deformable and extends from the connecting head portion (38); and a molded portion (53) which is provided in the connector housing (50) to integrally cover the ground-side electrode (21 B) of the capacitor (20) and the connecting head portion (38) of the ground-side terminal (32).