Cu引线超声键合动态过程有限元模拟

Finite Element Modeling of Dynamic Process of Copper wire Ultrasonic Wedge Bonding

引线键合是电子封装中一种重要的芯片互连技术,其中Cu引线的超声键合是目前研究的热点。利用ANSYS有限元软件建立了包括Cu引线、键合劈刀、焊盘以及芯片在内的超声楔焊模型,采用非线性有限元方法研究冲压和超声振动两个阶段的应力场变化,着重探讨超声振动阶段材料塑性变形量的突变,并分析超声功率改变时焊点结构中应力和应变的变化。

Wire bonding is one of the most important technologies for chip interconnection in microelectronic packaging, and currently copper ultrasonic bonding attracts more attention. A finite element model of dynamic process of ultrasonic wedge bonding was established including the Cu wire, the wedge tool, the pad and the Si chip by a commercial finite element code, ANSYS software. The change of the stress field of the wedge bond at the impact stage and the ultrasonic - applied stage was simulated by the non - linear method. The stepping up of the value of plastic - deformation when ultrasonic was applied was discussed. And the change of stress and strain in the bonding structure when the ultrasonic power is changed was analyzed.