Modelling aluminium wire bond reliability in high power OMP devices

In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is preferred and wedge wedge wire bonding is widely used. As a result of poor wire shape design, wedge break can be found. Additionally, for the in-shin wires, which are typically very high and can reach high temperatures, failure by wire melting can be reached. During this project, a parametric procedure has been successfully generated. This procedure is able to generate a 3D solid wire bond model, wedge-wedge. The model is able to describe coupled electro-thermal mechanical behaviour with contact conditions between the aluminium wire and the moulding compound. Preliminary stiffness evaluations show that the in shin wires are significantly weaker than the offset design (from die to leadframe). Preliminary thermal evaluations show that the wire geometry does not have a large influence on the resulting temperature.