(1. 清华大学材料科学与工程系，北京 100084； 2. 洛阳铜加工厂，洛阳 471039)
摘 要: 研究了合金元素对Cu-Ni-Si系列引线框架用铜合金性能的影响。发现合金中时效析出物具有与δNi2Si相似的晶体结构，Ni及Si元素含量对材料硬度和电导率有很大影响。当Ni及Si元素含量增大时，由于析出物数量增多，材料硬度增加；当Ni与Si 原子数之比小于2时，材料电导率明显下降，这是由于过剩Si元素以固溶原子形式存在，强烈损害材料电导率的结果。加入Zn元素后，保温过程中Zn元素在合金与Sn-Pb共晶焊料界面处偏聚，阻碍脆性金属间化合物层的形成，在425K保温1000 h后，铜合金与焊料间结合良好。
关键字: 引线框架；铜合金；硬度；电导率；钎焊
（1. Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R.China
2. Luoyang Copper Working Plant, Luoyang 471039, P.R.China）
Abstract:The effects of alloying elements on the properties of Cu-Ni-Si alloys for lead frame were investigated. It was found that the crystal structure of the precipitates in Cu-Ni-Si alloy is similar to δ-Ni2Si . The hardness and electrical conductivity of materials can be affected remarkably by the contents of Ni and Si elements. The hardness of alloys will increase along with the increasing of Ni, Si contents. The electrical conductivity will decrease significantly if the proportion of Ni and Si contents (in atom) is less than 2∶1 because the surplus Si element will exist as solute atoms in Cu matrix. Because of the addition of Zn element, the joint between copper alloy and Sn-Pb solder was improved remarkably as the formation of the intermetallic compound layer at the interface was impeded by a segregation layer of Zn element during heat treatment.
Key words: lead frame; copper alloys; hardness; electrical conductivity; solder
