日本住友金属矿业公司已发展了一种用于大规模集成电路引线、纯度为99.9999％的铜丝。高纯铜是用99.99％纯铜经电解提纯获得。此种具有0.2μΩcm比电阻的铜丝有可能取代传统用的金丝。另外,日本矿业公司也已发展了一种 Sumitomo Metal Mining Japan has developed a copper wire for large scale integrated circuit leads with a purity of 99.9999%. High purity copper is 99.99% pure copper obtained by electrolytic purification. Such a copper wire with a specific resistance of 0.2 μΩcm may replace the conventional gold wire. In addition, Japanese mining companies have also developed one