Thin mold array package warpage control study

The increasing demand for lighter and multi-functional consumer electronic products has challenged package development to focus on thinner and smaller packages. This package requirement trend has pushed glob top BGA and mold array package (MAP) development to a new level. Motorola has been developing the thinner BGA packages, including thin mold array packages, to be space and cost effective. This paper presents the study on the thin MAP BGA substrate core material evaluation, and also on warpage control in the package assembly process. The test vehicle is a 224 I/O thin MAP package. The study included two different substrate core materials. The study also looked at the substrate supplier´s manufacturing process effects on the substrate warpage performance. Three different substrate manufacturing process were evaluated. The study compares these substrates´ warpage performance during the assembly processes. One molding compound was used in the evaluation. The package warpage was closely monitored after each assembly process and the results were studied using a statistical analysis tool. The interfacial integrity of the packages was examined by using acoustic microscopy with CSAM after moisture soak at moisture sensitivity levels MSL 1 and 2, PTH and autoclave. The results show that the warpage has a strong effect on package manufacturability and also on the package MSL performances. The results also indicate that the substrate supplier´s manufacturing process has a strong effect on the package assembly processes