Consideration of Mold Compound Cure Shrinkage in Finite Element Modeling

In this work, the substrate warpage was predicted using the four modeling methods: MeanCTE, InsCTE, CureCTE + MeanCTE and EqvCTE. Both laminate and leadless leadframe substrates were evaluated. The effect of mold compound chemical cure shrinkage on the substrate warpage was also investigated. A laser profilometer was employed to measure the warpage of the laminate and leadless leadframe substrates. Our findings showed that CureCTE + MeanCTE modeling method correlated well with the warpage measurement. This method was employed to further evaluate different mold compounds on the substrate warpage for leadless leadframe substrate. Therefore, the effect of mold compound chemical cure shrinkage is important and has to be implemented appropriately in the model for accurate warpage predictions. It can also be used in package designs and material selections to eliminate the coplanarity issue and achieve an improved assembly process yield in future developments.