Overmold technology applied to cavity down ultrafine pitch PBGA package

Abstract

The transfer molding technology is normally used for leadframe type packages and chip-up PBGA (Plastic Ball Grid Array) packages. This technology has been applied to cavity down PBGA packages where, normally, a liquid epoxy is dispensed by a needle in the cavity in order to cover the device and gold wires without exceeding the solder ball height plane. The new encapsulation approach using transfer molding process as well as the debug/qualification method and results using an ultrafine pitch wirebond PBGA process are described.