Solid type cavity fill and under fill materials for new IC packaging applications

IC packaging methods are diversified drastically today, because of the requirement for the package to perform the IC characteristics itself. The majority of encapsulating material in the IC packaging market is transfer molding. However, the transfer molding method is hard to apply to some new applications such as flip chip, cavity fill type PPGA (plastic pin grid arrays), BGA (ball grid arrays), and tape carrier packages. Liquid type resins are mainly used for these new applications in the current market. However, there are several serious disadvantages to using liquid type resins. The problems are poor processability and reliability. Under these circumstances, we focused on the improvement of the two disadvantages for liquid resin applications on flip chip and cavity fill type PPGA and BGA. Our newly developed materials are solid compounds at room temperature. These compounds are designed based on the study of reliability and processability. The base resin systems are selected by moisture performance and fluidity characteristics.