Ultrahigh-purity copper (UHPC) of five to seven nines has been developed, and commercial production has been started by Nippon Mining and Metals Company. This value-added copper has such characteristics as high electrical and thermal conductivity at very low temperatures, low softening temperatures, and high workability due to fewer nonmetallic inclusions and voids as compared with conventional high-purity copper (i.e., four nines). Taking advantages of these characteristics, UHPC is being applied to bonding wire of integrated circuits and cables for audio devices.
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H. Okamoto et al., “Development and Low-Temperature Properties of High-Purity Copper,” J. Mining and Materials Proc. Inst. of Japan, 105 (1989), pp. 150–153.
M. Kato, “Copper Taking an Active Part in Hi-Tech Field,” Scientific American, Japan Edition, 23-1 (1993), pp. 30–33.
H. Bruning, J. Le. Hericy, and K. Lucke, “Production of Ultra High Purity Copper by Nitrate Electrolysis and Floating Zone Melting,” Ann. Chim. Fr., 10 (1985), pp. 121–133.
J.S. Smart, Jr., A.A. Smith, Jr., and A.J. Phillips, “Preparation and Some Properties of High-Purity Copper,” Trans. AIME, 143 (1941), pp. 272–286.
T. Ogata et al., “Copper Wires Used for Transmitting Sounds or Images,” U.S. patent 4,792,369 (December 20, 1988).
T. Nara and Y. Yamada, “Zone Refining of Pure Copper,” J. Jpn. Inst. of Metals, 24 (1960), pp. 460–464.
A. Mori et al., “Production Method of High Purity Copper for Semiconductor Use and Evaluation of the Quality (Report-1),” J. High Temperature Society, 13-1 (1987), pp. 18–29.
H.R. Lowry and R.T. Frost, “General Electric Levitation Casting (GELEC) Process” (Paper presented at TMS-AIME Fall Meeting, 1984).
A. Ohno, “New Continuous Casting Process Using a Hot Mould O.C.C.,” Bulletin of the Jpn. Inst. of Metals, 23 (1984) pp. 773–778.
M. Kato, “Properties and Applications of High-Purity Copper,” Materia Japan, 33-1 (1994), pp. 74–77.
K. Mimura et al., “Residual Resistivity Ratio of High-Purity Copper,” (unpublished paper).
T. Sakai and Z. Xu, “Effect of Purity on Static Grain Growth in Dynamically Recrystallized Copper,” J. Jpn. Inst. of Metals, 59-2 (1995), pp. 125–132.
M. Kanno and G. Itoh, “Ductility Loss and Its Improvement in Copper and Copper Base Alloys at Elevated Temperatures,” Bulletin of the Jpn. Inst. of Metals, 27-7 (1988), pp. 532–539.
H. Kimura et al., “Application of Large Crystal Copper Conductor in AV Equipment Interconnecting Cable,” Hitachi Cable Review, no.9 (1990), pp. 99–104.
E. Ono, M. Kato, and T. Ogata, “Production & Application of 6N Copper to Audio,” Preprints of AES 4th Regional Convention, Tokyo, D-7 (1989), pp. 186–189.
E. Ono and M. Kato, “Production & Application of 6N Copper to Audio,” Preprint of the 87th AES Convention, 2865 (A-1) (1989).
E. Ono and M. Kato, “Application of High-Purity Copper to Audio,” Proceeding of Rare Metals ′90, B3-10 (1990), pp. 445–448.
M. Kato, “Application of UItra-HighPurity Copper for Electric Wires and Conductors,” Proceeding of UHPC-94 (1994), pp. 441–445.
N. Fujio et al., “Development of High Strength Copper Alloy Wire and Bend Resistant Cable,” Tatsuta Technical Rev., 12 (1991).
H. Nakayama and Y. Satomi, “Characteristics of New TAB Products Using Special Copper Alloy,” ITAB ′91 Proceeding (1991).
M. Kato, “High Conductivity Copper Alloys with Excellent Workability and Heat Resistance,” U.S patent 5,077,005 (December 31, 1991).
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Kato, M. The production of ultrahigh-purity copper for advanced applications. JOM 47, 44–46 (1995). https://doi.org/10.1007/BF03221340
- Nonmetallic Inclusion
- Copper Foil
- Audio Device
- High Softening Temperature
- Bend Fatigue Strength