Cu-Co-Ni-Si Copper Alloy Composition for High-Bend Electronic Parts

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Solution Overview

Problem

Conventional copper alloys face challenges in achieving high bending workability, particularly with complex processing techniques such as notch bending, 180° close bending, and hammer bending, while maintaining high strength and electrical conductivity.

Innovation Solution

A copper alloy with specific composition and microstructural control, including an average Taylor factor of 3.5 or less, crystal grain size of 10 μm or less, and a mass ratio of (Ni+Co)/Si between 3 and 5, to achieve enhanced bending workability, strength, and electrical conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional copper alloys are used to achieve high strength and electrical conductivity, then the basic characteristics are satisfied, but bending workability deteriorates under complex processing conditions

Engineering Contradiction:
Improve0.2% yield stressVSAvoidbending workability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention changes the microstructural parameters by controlling crystal grain size to 10 μm or less and average Taylor factor to 3.5 or less through specific composition ratios (Ni+Co)/Si = 3 to 5, enabling simultaneous achievement of high strength (700 MPa or more) and improved bending workability for complex processing

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite alloy system combining Cu-Co-Ni-Si with specific element ratios, where the interaction between multiple elements creates a microstructure that simultaneously provides high strength and enhanced bending workability, overcoming the limitations of conventional single-element copper alloys

Inventive Principle:
Principle #40Composite materials

2Strength

If higher strength is achieved in copper alloys, then the 0.2% yield stress increases, but electrical conductivity deteriorates

Engineering Contradiction:
Improve0.2% yield stressVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention optimizes the composition parameters by controlling the (Ni+Co)/Si ratio to 3 to 5 and limiting individual element contents (Co: 0.5-2.5%, Ni: 0.1-1.0%, Si: 0.05-0.5%), achieving a balance where strength reaches 700 MPa or more while electrical conductivity remains at 50% IACS or more

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If conventional copper alloys are used for simple bending, then basic processing is achievable, but complex processing (notch bending, 180° close bending, hammer bending) cannot be sufficiently performed

Engineering Contradiction:
Improveprocessing capabilityVSAvoidcomplex processing adaptability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The invention changes the microstructural parameters (crystal grain size ≤10 μm, Taylor factor ≤3.5) through controlled composition and processing, enabling the material to adapt to various complex processing methods including notch bending, 180° close bending, and hammer bending while maintaining high strength and workability

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 copper alloy exhibits improved bending workability, maintaining high 0.2% yield stress (700 MPa or more) and electrical conductivity (50% IACS or more), making it suitable for complex electronic component processing.

Implementation Method 1

Such copper alloy is a precipitation hardening type copper alloy, and its strength and electrical conductivity are improved by precipitating fine Ni—Si intermetallic compound particles in the copper matrix

Methodology Applied
Scientific EffectPrecipitation hardening: Precipitation Hardening

Data Source

PatentUS20250129451A1Copper alloys for electronic materials and electronic components
Publication Date: 2025.04.24 JX ADVANCED METALS CORP

AI summary

A copper alloy for electronic materials, in which an amount of Ni is 1.0% by mass or less, the copper alloy including 0.5 to 2.5% by mass of Co, and including Si such that a mass ratio (Ni+Co)/Si is 3 to 5, the remainder consisting of copper and inevitable impurities, wherein an average Taylor factor under plane strain that elongates in a direction perpendicular to a rolling direction and reduces plate thickness is 3.5 or less, a crystal grain size is 10 μm or less, and a 0.2% yield stress in the rolling direction is 700 MPa or more, and an electrical conductivity in the rolling direction is 50% IACS or more.