IC键合铜线材料的显微力学性能研究

Micro-mechanical property study of IC copper bonding wire material

用于IC(集成电路)的键合铜线材料具有低成本、优良的导电和导热性等优点,但其高硬度容易对铝垫和芯片造成损伤,因此对其硬度的测量是一项关键技术。纳米压痕测量技术可以方便、准确地测量铜线材料的显微硬度值和其他力学性能参数。描述了纳米压痕测量技术的原理以及对铜线材料样品进行纳米压痕测量的参数选择,进行了测量试验。结果表明,原始铜线、FAB(金属熔球)、焊点的平均硬度分别为1.46,1.51和1.65GPa,为键合铜线材料的选择和键合工艺参数的优化提供了依据。

The most IC interconnections used gold wire. Recently, copper bonding wire is developed with its higher conductivity, thermal conductivity and lower cost, but its higher hardness, peeling the aluminum pad and making the die crack happened easily, which becomes one of the main problems in the copper wire bonding process. Newly developed nanoindentation measuring technique can not only detect the micro hardness of materials, but also get the material’s elastic modulus, fracture toughness and other materials properties. The principle of the nanoindentation measuring technique and describe how to select test parameters of nanoindentation were introduced. The experiment results show that the average hardness of original copper wire, FAB, bonded ball are 1.46, 1.51, 1.65 GPa, respectively. The nanoindentation test results of copper wire, FAB （free air ball） and its bonded point combining with their microstructure observation could turn into one of the characterization method in the copper wire material selection and bonding process parameters optimization.