焊接空洞对功率器件可靠性的影响与调控

Influence and Regulation of Voids in the Solder Layer on Reliability of Power Devices

焊接空洞会导致功率器件在使用过程中结温上升,应力增大,从而降低整个器件的可靠性与寿命。不同大小、不同位置的空洞所产生的影响有所不同。通过Ansys仿真计算了不同大小的空洞处于不同位置时结温与应力的值,建立了结温/应力与空洞大小、位置的三维关系图,对评估现有工艺在空洞调控方面的好坏以及如何降低空洞对结温、应力的影响具有指导意义。结果表明,空洞的孔径越大,位置处于焊料层中心或边缘位置时,对器件的影响越大。

The voids in the solder layer will lead to the increase of junction temperature and stress during the application of power device,so as to reduce the reliability and service life of the device.The influence of voids varies by size and position.The junction temperature and stress of voids with different sizes at different positions are calculated by Ansys.At the same time,the three-dimensional relationship diagram between junction temperature/stress and the size and position of voids is established,which provides guiding significance for not only evaluating the quality of existing technology by voids regulation but also reducing the influence of voids on junction temperature and stress.The results show that the larger the void size is,and when the void is located at the center or edge of the solder layer,the greater the influence on the device will be.