AgAuPd中熵合金力学、热力学和电学性质的第一性原理研究

在微电子封装领域,键合Ag线具有较好的电学性能优势被广泛应用,但纯银线因存在强度低、高温易失效等缺点不能满足大功率器件的使用,因此本工作拟通过设计等原子比AgAuPd中熵合金作为替代纯Ag线的新型键合材料。本文通过SQS模型构建了等原子比AgAuPd中熵合金晶体模型,利用第一性原理计算了AgAuPd中熵合金在不同压力下的弹性性质(弹性常数、弹性模量、剪切模量)、热力学性质和电子结构。预测出AgAuPd中熵合金随压力的增加具有较好的结构稳定性、良好的塑性、高温稳定性以及优良的导电性,具有成为键合材料的潜力。利用第一性原理计算AgAuPd中熵合金加压下的力学、热力学和电学性质,对开发新型键合Ag基丝具有一定的理论指导意义。

First-principles studies on mechanical, thermodynamic and electrical properties of AgAuPd medium entropy alloy

Ag bonding wires are widely applied to the field of microelectronic packaging because of their good electrical properties. However, pure Ag wires possess the disadvantages of low strength and high temperature failure, and can not be used in high power devices. Therefore, we try to design an equal atomic AgAuPd medium entropy alloy as new bonding material to replace pure Ag wires. In this work, based on the SQS model, the crystal structure of AgAuPd medium entropy alloy is established. The elastic properties (elastic constants, elastic modulus, shear modulus), thermodynamic properties and electronic structure of AgAuPd medium entropy alloy under different pressures are calculated by first principle. It can be predicted that AgAuPd medium entropy alloy has good structural stability, good plasticity, high temperature stability and good conductivity with increasing of pressure. AgAuPd medium entropy alloy has great potential to become a bonding material. Through using the first principle to calculate the mechanical, thermodynamic and electrical properties of AgAuPd medium entropy alloy under different pressure, it has certain theoretical significance for the development of new Ag base bonding wires.