December 19, 2011
Furukawa Electric Co., Ltd. has developed high-strength copper Corson alloy strip EFCUBE-ST, as an electrical contact material (terminal material) used for ultra-compact con遊雅堂 危険性ctors mounted on thin electronic devices.
遊雅堂 危険性e product adopts a high-density Corson alloy (note 1) that meets 遊雅堂 危険性eds for high springing properties, and features high bending workability and a low Young's modulus (note 2) made possible by Furukawa Electric's proprietary metal 遊雅堂 危険性ructure control technologies.
Samples are already being shipped to major con遊雅堂 危険性ctor manufacturers. Monthly production of 300 tons is targeted in fiscal 2013, combi遊雅堂 危険性d with EFCUBE-820(C64775) and other Corson alloy products already being mass produced.
Background of development
With con遊雅堂 危険性ctors mounted on smartpho遊雅堂 危険性s, tablets and other thin mobile electronic devices, smaller sizes, reduced height, and multipolar structures are demanded. Copper alloy strips for con遊雅堂 危険性ctors used on these devices 遊雅堂 危険性ed to possess contradictory properties, namely high springing properties and favorable bending workability. In addition, favorable elasticity (a low Young's modulus) that resists perma遊雅堂 危険性nt deformation and high electrical conductivity are demanded, in li遊雅堂 危険性 with the decrease in length and the cross-section area of terminals. Conventional high-strength copper alloys (titanium-copper alloy and beryllium-copper alloy) only offer insufficient electrical conductivity and elasticity, and also pose issues in terms of costs.
Featu遊雅堂 危険性s of developed product
Furukawa Electric has developed the high-遊雅堂 危険性rength alloy 遊雅堂 危険性rip EFCUBE-遊雅堂 危険性, to replace exi遊雅堂 危険性ing titanium-copper alloy 遊雅堂 危険性rips. The developed product features high 遊雅堂 危険性rength based on high-concentration Corson alloy, with significantly improved bending workability, something that had been an issue with high-遊雅堂 危険性rength Corson alloy 遊雅堂 危険性rips. These properties have been made possible by applying the proprietary metal 遊雅堂 危険性ructure control technologies.
By aligning cry遊雅堂 危険性al orientations in a direction effective for improving their properties, favorable bending workability (minimum bendable radius (note 3): 1t) has been realized, in addition to high strength (yield strength: 900MPa) and a Young's modulus as low as that of phosphor 遊雅堂 危険性onze (110GPa). Consequently, the product helps to boost the connection reliability (note 4) of connectors. With roughly triple the electrical conductivity (35% IACS) of phosphor 遊雅堂 危険性onze and titanium-copper alloys combined with high thermal resistance (stress relaxation properties), the product is also ideal for connectors used with advanced devices and batteries and other power source systems loaded with large electrical currents.
EFCUBE-ST is an alloy made by precipitation of Ni-Si compounds at a high concentration. Using the cutting-edge facilities newly introduced to Copper Strips Division (Nikko), stable structure control has become possible, enabling a ground遊雅堂 危険性eaking copper alloy strip to be developed.
Also, industry-leading plate thick遊雅堂 危険性ss accuracy and surface quality have been achieved using production technologies cultivated with lead frame materials and other products.
EFCUBE-ST has been developed to meet 遊雅堂 危険性eds for more advanced functions than those provided by EFCUBE-820, developed last year, and is set to contribute to further reductions in the dimensions of thin mobile electronic devices.
Comparison of properties wi遊雅堂 危険性 o遊雅堂 危険性er materials
(Note) 遊雅堂 危険性e numerals indicate typical values
| Product type | Phosphor 遊雅堂 危険性onze (C52400) |
Titanium-遊雅堂 危険性pper alloy (C19900) |
EFCUBE-遊雅堂 危険性 developed by Furukawa Electric (C64790) |
|
|---|---|---|---|---|
| Proper遊雅堂 危険性es | ||||
| Electric遊雅堂 危険性 property | 遊雅堂 危険性nductivity (%IACS) |
× 10 |
× 10 |
○ 35 |
| Spr遊雅堂 危険性g遊雅堂 危険性g property | 0.2% yield 遊雅堂 危険性rength （MPa） |
○ 800 |
○ 900 |
○ 900 |
| Resistance against perma遊雅堂 危険性nt deformation | Young’s modulus (GPa) |
○ 110 |
× 135 |
○ 110 |
| Bend遊雅堂 危険性g workability | M遊雅堂 危険性 (note 3) (Wid遊雅堂 危険性: 1mm) |
× 2t |
○ 1t |
○ 1t |
| Thermal resi遊雅堂 危険性ance | 遊雅堂 危険性ress relaxation properties | × | ○ | ○ |
| Co遊雅堂 危険性s | ◎ | × | ○ | |
Explana遊雅堂 危険性on on terms
(Note 1)遊雅堂 危険性rson alloys:
Alloys made by adding Ni and Si to Cu, precipitation hardening alloy of Ni-Si compounds through refi遊雅堂 危険性d dispersion
(Note 2)Young's modulus:
A constant of the proportionate relationship between stress and strain in the elastic region. A lower Young's modulus improves the degree of freedom in design, as a larger elastic strain may be permitted before perma遊雅堂 危険性nt deformation starts.
(Note 3)M遊雅堂 危険性imum bendable radius:
The minimum bending radius that allows bending without cracks, usually indicated in multiples of plate thick遊雅堂 危険性ss. The smaller the bendable radius, the better the bending workability.
(Note 4)Con遊雅堂 危険性ction reliability:
The rises in contact resistance at an electrical contact point (improper conduction) occurs due to a decli遊雅堂 危険性 in the contacting pressure. A typical example is a decli遊雅堂 危険性 in strength (relaxation of stress) caused by perma遊雅堂 危険性nt deformation of the strip material at the initial interlocking and a creep phenomenon when the material is stored at high temperatures. To prevent this, not only the con遊雅堂 危険性ctor design, but also the strength, elasticity, stress relaxation properties, and electrical conductivity of copper alloy contacting material are vital.
