Roughened Nickel-Plated Sheet for Lower-Temperature Joining

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Solution Overview

Problem

Conventional roughened nickel-plated materials face challenges in achieving high adhesion with another member while requiring extended joining times or elevated temperatures, which increases environmental load and reduces productivity.

Innovation Solution

A nickel-plated metal sheet with a roughened nickel layer having a ten-point mean roughness Rzjis of 1.0 to 4.5 µm and a Density Of Peaks Spd of 20000/mm² or higher, along with optional additional layers like a zinc layer, improves adhesion and allows for shorter joining times and lower temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the protrusions of roughened nickel are formed tall to increase adhesion strength with another member, then adhesion strength is improved, but joining time needs to be lengthened or joining temperature needs to be raised

Engineering Contradiction:
Improveadhesion strengthVSAvoidjoining time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The invention changes the surface roughness parameters from conventional tall protrusions (Rzjis > 4.5 μm) to optimized protrusions with Rzjis of 1.0 to 4.5 μm and Spd of 20000/mm² or higher. This parameter optimization allows resin to penetrate to the roots of protrusions more easily, achieving high adhesion strength while reducing joining time and temperature requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of forming very tall protrusions that would ensure resin penetration but require excessive joining time, the invention uses moderately sized protrusions (Rzjis 1.0 to 4.5 μm) with high density (Spd ≥ 20000/mm²). This partial action approach achieves sufficient resin penetration and adhesion strength without the time penalty of excessive protrusion height.

Inventive Principle:
Principle #16Partial or excessive action

2Strength

If the protrusions of roughened nickel are formed tall to increase adhesion strength with another member, then adhesion strength is improved, but joining temperature needs to be raised

Engineering Contradiction:
Improveadhesion strengthVSAvoidjoining temperature
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The invention optimizes surface roughness parameters to Rzjis of 1.0 to 4.5 μm and Spd of 20000/mm² or higher, which creates a surface morphology that facilitates resin flow and penetration at lower temperatures. This eliminates the need to raise joining temperature to achieve adequate adhesion strength.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The optimized roughened nickel surface acts as an intermediary structure with moderate-height, high-density protrusions that facilitate resin penetration without requiring high temperature. The specific surface morphology serves as a mediator between the metal substrate and resin, enabling effective bonding at reduced temperatures.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If conventional roughened nickel layer is used, then adhesion with base material is maintained, but resin is less likely to flow to roots of roughness-forming protrusions

Engineering Contradiction:
Improveadhesion of plating layer to base materialVSAvoidresin flowability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The invention changes the surface roughness parameters from conventional settings to optimized values (Rzjis 1.0 to 4.5 μm, Spd ≥ 20000/mm²). This creates protrusions that are tall enough to provide adhesion anchor points but not so tall as to impede resin flow to their roots, resolving the contradiction between adhesion strength and resin flowability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a dynamic balance in protrusion geometry where the height and density are optimized to simultaneously satisfy two opposing requirements: providing sufficient anchor points for adhesion while maintaining channels for resin penetration. The specific parameters (Rzjis 1.0 to 4.5 μm, Spd ≥ 20000/mm²) represent this optimized dynamic state.

Inventive Principle:
Principle #15Dynamics

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 nickel-plated metal sheet enhances adhesion with another member while reducing joining time and temperature, thereby decreasing environmental impact and improving productivity.

Implementation Method 1

a roughened nickel layer formed on at least one side on the base material. A ten-point mean roughness Rzjis on an outermost surface on a side of the roughened nickel layer is 1.0 to 4.5 μm, and a Density Of Peaks Spd on the outermost surface on the side of the roughened nickel layer is 20000/mm² or more

Methodology Applied
Scientific EffectMechanical interlocking:

Data Source

PatentEP4653585A1Nickel plated metal sheet
Publication Date: 2025.11.26 TOYO KOHAN CO LTD
  • EP4653585A1 patent drawingFigure 1
  • EP4653585A1 patent drawingFigure 2
  • EP4653585A1 patent drawingFigure 3

AI summary

[Object] Disclosed is a nickel-plated metal sheet, which includes a plating layer having adhesion with a base material and adhesion with another member, and further is capable of shortening a joining time or lowering a joining temperature compared to the conventional technology, when joined with another member. [Solving Means] The nickel-plated metal sheet includes a base material made of metal, and a roughened nickel layer formed on at least one side on the base material. A ten-point mean roughness Rzjis on an outermost surface on a side of the roughened nickel layer is 1.0 to 4.5 µm, and a Density Of Peaks Spd on the outermost surface on the side of the roughened nickel layer is 20000/mm2 or higher.