Ni-Sn Plated Connecting Material Friction Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing materials for connecting members, such as those used in electrical contact terminals, face challenges in minimizing friction and preventing increases in contact resistance during repeated fine sliding, which can lead to oxidation and reduced reliability.

Innovation Solution

A material comprising a Ni-plated stainless steel plate with a specific roughness motif mean depth of 1.0 µm or more and a Sn plating layer of 0.3 to 5 µm thickness, where the Sn layer remains in concave portions to enhance lubricity and prevent abrasion, maintaining initial contact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a Ni plating layer with smooth surface is formed on stainless steel, then manufacturing precision is improved, but friction increases and contact resistance increases during repeated sliding

Engineering Contradiction:
Improvesurface smoothnessVSAvoidcontact resistance stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention applies different surface quality requirements to different functional zones: the overall surface maintains adequate smoothness for manufacturing, while specific micro-concave portions provide localized Sn layer retention to reduce friction and maintain contact resistance. This resolves the contradiction by making different parts of the surface serve different functions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The concave portions are pre-formed on the Ni plating layer before final assembly, creating predetermined zones where the Sn plating layer will be retained during sliding. This preliminary structuring ensures that when sliding occurs, the Sn layer remains in these pre-designed locations to continuously reduce friction and maintain electrical contact.

Inventive Principle:
Principle #10Preliminary action

2Strength

If stainless steel is used as base material, then mechanical strength and stress relaxation resistance are improved, but friction coefficient increases during repeated sliding

Engineering Contradiction:
Improvemechanical strengthVSAvoidfriction coefficient
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention creates a composite structure with multiple layers: stainless steel base material providing mechanical strength, Ni plating layer providing adhesion and surface structure, and Sn plating layer providing low friction. The concave portions in the Ni layer create Sn-rich zones that specifically address the friction issue while the stainless steel base maintains its strength advantages.

Inventive Principle:
Principle #40Composite materials

3Reliability

If roughness motif mean depth is increased to retain Sn layer, then lubricity is improved, but manufacturing complexity increases

Engineering Contradiction:
ImprovelubricityVSAvoidsurface structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention optimizes the roughness motif mean depth to a specific range (0.5 µm to 2.0 µm) that provides sufficient Sn layer retention for lubricity while remaining manufacturable. This parameter optimization balances the competing requirements of surface functionality and manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

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 material effectively reduces friction and suppresses increases in contact resistance during repeated fine sliding, maintaining reliable electrical connections by preventing exposure of the stainless steel base and oxidation.

Implementation Method 1

a Sn plating layer which has a thickness of 0.3 to 5 µm is formed on the Ni plating layer

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

a mean depth R of a roughness motif is 1.0 µm or more in at least one direction on a surface of the Ni plating layer

Methodology Applied
Scientific EffectAbrasion resistance: Abrasion

Data Source

PatentEP3147391B1Connecting component material
Publication Date: 2019.11.20 NISSHIN STEEL CO LTD

AI summary

A connecting component material used as a material constituting a connecting component, wherein the connecting component material is obtained by using a Ni-plated metal plate in which a Ni plating layer is formed on the surface of a metal plate, and the average depth (R) of a surface roughness motif in at least one direction on the surface of the Ni plating layer is 1.0 µm or above, and by forming a Sn plating layer having a thickness of 0.3 to 5 µm on the Ni plating layer of the Ni-plated metal plate; the connection component material makes it possible to reduce friction and minimize abrasion of the material when a connecting component such as an electrical connection terminal is fitted, and to improve the reliability of a stable electrical connection; and the connecting component material can be used in e.g., electrical contact components such as lead frames, harness plugs, and connectors used in electrical and electronic devices and the like.