〉〉New ProductsHigh Conductive and High Strength Copper Alloy Wire
FWUHD-XT for Smart Devices
INTRODUCTION

As electronic devices are becoming more multi-functionaland wearable, demand for smaller and lighter parts isincreasing. In addition, electric wires for equipment wiring
are required high conductivity from the perspective of theincrease in the current and the increase in efficiency forenergy saving. On the other hand, ultra-thin diameter
cables and coils used in small devices need to be durable
against bending and vibration. In particular, robot cables,
whose demand has been increasing in recent years, musthave a high flexural-fatigue resistance and a high twist
characteristic. Therefore, we have developed theFWUHD-XT series, which has an extremely excellent balance of the electrical and the mechanical characteristics
as a copper alloy wire. As this product has both the highconductivity and the high strength, it can be used in awide range of fields such as wearable devices, electronic
device connection cables and medical cables.

2.

FEATURES

As the FWUHD-XT series uses our unique casting process and microstructural control process, it is superior to
general-purpose copper alloy wires and common Cu-Ag
alloy wires currently on the market with respect to thefollowing points: (1) Achievement of the high electricalconductivity and the high tensile strength at the sametime, (2) flexural-fatigue resistance, and (3) wire drawability.
(1) Achievement of the high electrical conductivity and thehigh tensile strength at the same time
Table 1 shows various typical characteristics. In addition, Figure 1 shows a comparison of the relationshipbetween the electrical conductivity and the tensile
strength with those of a typical copper alloy wire. This
product has achieved an improvement in strength ofapproximately 350 to 550 MPa compared to a generalpurpose alloy with the same conductivity. This wire has asuperior electrical conductivity and a tensile strengthcompared to a common Cu-Ag alloy wire (FWUHD-Agseries) that we have been manufacturing.

Table 1

Material properties.
FWUHD-XT
20XT

40XT

Tensile strength

MPa

1,100

1,400

Electrical Conductivity

%IACS

82

72

Thermal conductivity

W/m・K320

Youngʼs Modulus

GPa

125

Specific gravity−8.9

TPC（C1100）

Cu-Sn alloyFWUHD-Ag

FWUHD-XT

100

Electrical conductivity / %IACS

1.

TPC（C1100）

90

80

290

Cu-2％Ag

20XT
40XT

Cu-0.15％Sn
Cu-0.3％Sn70

Cu-4％Ag
Cu-0.7％Sn

60
50
400

600

800

1,000

1,200

1,400

1,600

Tensile strength / MPa
Figure 1

Relationship between the electrical conductivity andthe tensile strength of various copper alloy wires.

(2) Flexural-fatigue resistance
Figure 2 shows the evaluation method of the flexural
fatigue. Figure 3 shows a comparison of the flexural
fatigue resistance. The FWUHD-XT series exhibited a
flexural life that is approximately two to three times longer
than common Cu-Ag alloys of the same composition,
which has an excellent durability against repeated bending and vibration. For example, the FWUHD-XT series canachieve a mechanical strength and a flexural fatigue life
equivalent to or higher than those of Cu-4%Ag alloy wires
which are obtained using conventional processes, butwith a smaller amount of added Ag. Therefore, it is possible to improve conductivity while maintaining conventional strength, and to reduce the amount of expensive Agused.

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High Conductive and High Strength Copper Alloy Wire FWUHD-XT for Smart Devices

One-side bending angle= 90°

CONCLUSION

The FWUHD-XT series is a Cu-Ag alloy wire that has abalance between the conductivity and the tensile strength
at a higher level with our unique manufacturing process.
Due to its characteristics and good workability, it contributes to the miniaturization and multi-performance of various transmission cables, robot cables, etc., and is
expected to be used in high-performance electronicdevices.

R=6 mmTest material
Weight=30 gFigure 23.

Evaluation method of a flexural fatigue life.

For more information, please contact:
Electric Conductor Division
E-mail: fec.doudenzai@furukawaelectric.com

Flexural fatigue life / time

80,00060,00040,00020,0000

FWUHD-Ag

Cu-2%Ag
Figure 3

Cu-4%AgFWUHD-XT

20XT

40XT

Comparison of the flexural fatigue life between theFWUHD-XT and common Cu-Ag wires.

(3) Wire drawability
This series has an excellent wire drawability and can beprocessed into ultra-fine wires of φ50 μm or less. Our
melting and casting, and processing technology, whichtakes active measures to remove foreign substances,
reduces the amount of foreign substances contained inalloy wires by approximately 60% compared to generalprocesses, significantly reducing the risk of property
deterioration and wire breakage during ultra-fine diameter
wire drawing.

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