Multi-layer molded plastic package

The authors describe a multilayer molded (MM) plastic package. Internal to the plastic body, the package contains a pair of power and ground planes for improved electrical and thermal performance. These planes are attached to the leadframes at the piece part level. The change in the leadframe does not change the conventional plastic package assembly process. The planes significantly reduce the power-ground loop inductance and increase the power-ground capacitance, making it ideal for high-speed device operation. Manufacturability of both the piece part and the package is taken into account during the package design stage. The design is suitable for high-volume, low-cost piece part production. The lead fingers at the wire bond targets are resistant to handling damage and to any movement at elevated wire-bond temperature. Restricting the lead fingers to a fixed position minimizes damage to a bonded wire prior to encapsulation. Much smaller silicon chips than are possible with conventional single-layer packages can be packaged in this design. The MM package provides flexibility in allocating the power and ground pads on the chip