Electrodeposited Copper Alloy Foil with Metal Oxide Dispersion

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Solution Overview

Problem

Conventional electrodeposited copper foils experience significant reduction in mechanical strength when heated to high temperatures due to the decomposition of organic additives incorporated in the grain boundaries, leading to thermal degradation and loss of structural integrity in applications requiring high temperature stability.

Innovation Solution

The development of an electrodeposited copper alloy foil with ultra-fine particles of metal oxides, such as tungsten, dispersed in a copper matrix, using a low chloride ion concentration electrolyte without organic additives, which maintains mechanical strength and electrical conductivity even at elevated temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional electrodeposited copper foil is heated to 300°C for lamination processing, then the polyimide layer can be formed, but the copper foil undergoes recrystallization and softening causing dimensional changes and warping

Engineering Contradiction:
Improvelamination processingVSAvoiddimensional accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the compositional parameters of the copper foil by adding specific alloying elements (Ti: 0.01-0.06 mass%, Mo: 0.01-0.06 mass%, W: 0.01-0.06 mass%) to modify the thermal behavior. These additions raise the recrystallization temperature and prevent excessive softening at 300°C, thereby maintaining dimensional stability during lamination processing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite copper alloy foil combining copper with multiple alloying elements (Ti, Mo, W) in specific proportions. This composite structure leverages the high melting points and thermal stability of these elements to resist thermal softening and maintain structural integrity during heat treatment, preventing warping while enabling conventional lamination processes.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If rolled copper alloy foil is used to maintain dimensional stability at 300°C, then warping is prevented, but the mechanical strength and elongation are reduced

Engineering Contradiction:
Improvedimensional stabilityVSAvoidmechanical strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent optimizes the compositional parameters by controlling the content of alloying elements within specific ranges (0.01-0.06 mass% each for Ti, Mo, W). This parameter optimization ensures that the copper alloy maintains both dimensional stability at 300°C and adequate mechanical strength, avoiding the excessive strength loss associated with conventional rolled copper alloys.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality enhancement by incorporating specific alloying elements that provide targeted functional benefits: Ti and Mo for thermal stability, and W for strength retention. The controlled distribution of these elements creates localized regions of enhanced property that collectively achieve both dimensional stability and mechanical strength.

Inventive Principle:
Principle #3Local quality

3Strength

If electrodeposited copper foil with high mechanical strength is used, then the foil can withstand processing loads, but the mechanical strength is significantly reduced when heated to high temperatures due to organic additive decomposition

Engineering Contradiction:
Improvemechanical strengthVSAvoidheat resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent extracts and eliminates the harmful organic additives from the electrolyte composition. By using an inorganic electrolyte system without organic additives, the foil achieves high mechanical strength through controlled electrodeposition while avoiding the thermal degradation issue caused by organic additive decomposition at elevated temperatures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters by using an inorganic electrolyte system with specific metal salts (CuSO4, H2SO4, and alloying element salts) instead of organic-based electrolytes. This parameter change enables the deposition of a foil with high mechanical strength that maintains its properties at high temperatures, as inorganic compounds remain stable where organics decompose.

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 foil exhibits high tensile strength and heat resistance, with minimal thermal degradation, making it suitable for applications like flexible printed wiring boards and lithium ion secondary battery negative electrode current collectors, where high mechanical strength is required after heat treatment.

Implementation Method 1

electrodeposited copper alloy foil

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Implementation Method 2

electrolyte solution containing copper sulfate and metal salt

Methodology Applied
Scientific EffectElectrochemical reduction: Redox Reactions

Implementation Method 3

ultra-fine particles of metal oxides, such as tungsten, dispersed in a copper matrix

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 4

low chloride ion concentration electrolyte

Methodology Applied
Scientific EffectElectrolyte purification: Purification

Data Source

PatentUS9428840B2High strength, high heat resistance electrodeposited copper foil and manufacturing method for same
Publication Date: 2016.08.30 FURUKAWA ELECTRIC CO LTD

AI summary

Task: To provide an electrodeposited copper alloy foil with large mechanical strength under normal conditions, and that does not easily degrade due to heat when heated to about 300° C.Resolution Means: An electrodeposited copper alloy foil that includes a metal that exists as an oxide in a solution at pH4 or less or an oxide of the metal, and a method of manufacturing same.