Titanium Copper Foil Layering for Stronger Etched Camera Springs

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Solution Overview

Problem

Existing titanium copper foils used in autofocus camera modules suffer from low strength, leading to settling and inadequate etching properties, which hinder their functionality and performance in high-functionality cameras with multiple lenses.

Innovation Solution

A titanium copper foil with a fine layered structure achieved by controlling the solidification velocity during casting and warm rolling, ensuring a specific Ti concentration distribution, resulting in high tensile strength, improved etching properties, and reduced settling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If titanium copper foil is used to reduce raw material costs, then cost is reduced, but strength is lower causing settling

Engineering Contradiction:
Improvesettling resistanceVSAvoidtensile strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies parameter changes by precisely controlling the Ti concentration within 1.5-5.0% and implementing specific warm rolling temperature ranges (200-450°C) and rolling reduction ratios (10-50%). These parameter optimizations transform the titanium copper foil's microstructure and mechanical properties, achieving both cost reduction and improved strength to prevent settling

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by forming a fine layered structure through controlled solidification and warm rolling. The layered structure with alternating high-Ti and low-Ti regions acts as a composite architecture that enhances strength and settling resistance while maintaining the cost advantages of titanium copper alloy

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional titanium copper foil is used, then manufacturing cost is reduced, but etching properties are inadequate

Engineering Contradiction:
Improveetching propertyVSAvoidfunctionality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by creating regions with different Ti concentrations (high-Ti and low-Ti layers) within the foil structure. This non-uniform composition distribution provides locally optimized properties: the fine layered structure improves etching responsiveness in specific regions while maintaining overall structural integrity and functionality

Inventive Principle:
Principle #3Local quality

3Reliability

If strength is increased to prevent settling, then settling resistance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvesettling resistanceVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by implementing warm rolling at controlled temperatures (200-450°C) before final aging treatment. This preliminary warm rolling process pre-establishes the fine layered structure and dislocation distribution, which subsequently enhances the effectiveness of the aging treatment and achieves high strength with optimized manufacturing complexity

Inventive Principle:
Principle #10Preliminary action

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 titanium copper foil exhibits high tensile strength, excellent etching properties, and minimal settling, making it suitable for conductive spring materials in autofocus camera modules and other electronic devices.

Implementation Method 1

a heat treatment after the solutionizing treatment is divided into two stages, thereby increasing a range of Ti concentration (concentration difference) due to spinodal decomposition

Methodology Applied
Scientific EffectSpinodal decomposition:

Implementation Method 2

a solutionizing treatment, a sub-aging treatment, cold rolling, and an aging treatment

Methodology Applied
Scientific EffectSolutionizing treatment: Heat Treatment

Implementation Method 3

a solutionizing treatment, a sub-aging treatment, cold rolling, and an aging treatment

Methodology Applied
Scientific EffectAging treatment: Heat Treatment

Data Source

PatentEP3878988B1Titanium copper foil, extended copper article, electronic device component, and auto-focus camera module
Publication Date: 2026.01.14 JX ADVANCED METALS CORP
  • EP3878988B1 patent drawingFigure 1
  • EP3878988B1 patent drawingFigure 2
  • EP3878988B1 patent drawingFigure 3

AI summary

Provided is a titanium copper foil which has required high strength when used as a spring, has an improved etching property, and has decreased settling, and which can be suitably used as a conductive spring material for use in electronic device parts such as autofocus camera modules. The titanium copper foil according to the present invention contains from 1.5 to 5.0% by mass of Ti, the balance being Cu and inevitable impurities, wherein in a Ti concentration curve obtained by analyzing a cross section parallel to a rolling direction along a thickness direction by STEM-EDX, a lower concentration Ti layer having a Ti concentration less than an average value of Ti concentrations in the Ti concentration curve and a higher concentration Ti layer having a Ti concentration equal to or higher than the average value of the Ti concentrations in the Ti concentration curve are alternately present in a thickness direction, and wherein the titanium copper foil satisfies 1.0% by mass ≤ HH ≤ 30% by mass, and HH / HL ≥ 1.1, in which HH and HL are as defined in the present specification.