Analysis of the Effect of Hygrothermal Stress on Delamination of Plastic Sealed Devices

Epoxy resin is commonly used as the plastic sealing material for plastic encapsulated microcircuits. Epoxy resins can easily absorb moisture from the environment causing the sealant becoming wet, which can cause serious reliability problems when reflowed or other soldering processes are carried out. To address the above issues, this paper uses Anays finite element software to simulate and analyze the moisture absorption process of BGA plastic packaged devices in a humid environment and the reflow process after moisture absorption. Through the simulation experiments, we obtained the distribution of wet stress, thermal stress, hygrothermal stress and the deformation of BGA in the humidity field and temperature field, and then we analyzed and compared the effects of wet stress and thermal stress on the delamination of BGA. At the same time, the results of this paper were also compared with other literature, and the conclusions reached in this paper are generally consistent with the results of other literature, verifying the correctness of the results of this paper. From the experimental results of this paper, it can be seen that the moisture in the environment entering the plastic sealed device generates a greater impact on the reliability of the BGA device than the thermal stress generated by the reflow process, so the impact of moisture in the environment on the reliability of the plastic sealed device cannot be ignored.