Cu-Ni-Si系引线框架用铜合金成分设计

Design of Cu Ni Si copper alloy for lead frame

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δＮｉ２Ｓｉ 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４２５ Ｋ 保温１ ０００ ｈ后， 铜合金与焊料间结合良好。

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 Ni 2Si. 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. 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 Ni 2Si. 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.