Research On The Influence Of Aging Of Power Device Bonding Wire On Transmission Characteristics Based On High Frequency Effect

The power electronic system plays an important role in the process of electric transformation.The core component of power electronic system is power devices.It is the key that the high reliability of power devices which can ensure the safe and stable operation of power electronic system.The bonding wires of power devices is one of the most vulnerable parts to failure,at the same time,with the development of power devices towards high power and high switching frequency,the internal signal transmission quality of power devices has also attracted extensive attention from scholars at home and abroad.In the process of signal transmission,the aging of bonding wires will affect the signal transmission performance directly,so it is necessary to pay attention to the changes of transmission performance caused by the aging of bonding wires.Based on this,this thesis takes the bonding wires of power devices as the research object,considering its skin effect and proximity effect,studies the influence mechanism of bonding wires aging on the signal transmission characteristics of power devices.Firstly,this thesis introduces the skin effect and proximity effect of conductor under high frequency condition,as well as the change characteristics and basic principle of the current distribution in the conductor under the affected by two different effects.The electrical-thermal-stress model of bonding wires is constructed,and the aging mechanism of bonding wires is studied,the external characteristics of the aging of the bonding wires is analyzed,and the change rule of the location of proximity effect during the process of bonding wire lift-off is explored.Secondly,the influence mechanism of the geometrical parameters of bonding wires on the transmission performance of power devices is studied.The influence of bonding wires welding form and connection form on the signal transmission characteristics of power devices is also analyzed.The parasitic parameters of bonding wires under skin effect are extracted by finite element simulation,and the influence of skin effect on transmission characteristics of power devices is analyzed.The transmission performance of the devices with different wire diameters,arch heights,spans and connection modes is measured,and the variation rule of transmission performance is analyzed.Finally,the influence of the number change after aging and lift-off on the transmission performance is analyzed,and the power loss of conductors affected by proximity effect under high frequency condition is analyzed.Then the range of conductor loss caused by proximity effect is obtained.To explore the influence mechanism of aging number and lift-off position of bonding wires on transmission characteristics of power devices.Based on the above research,we can be found that the transmission characteristics of the bonding wires of the power devices under high frequency conditions,and the variation rule of the transmission characteristics after the bonding wire aging.The research results can be applied to the condition monitoring of the aging of bonding wires in power devices,which has practical significance to improve the reliability of power devices.