The electronics packaging industry has proliferated to a point where its technology is at least equally—the semiconductor technology it is designed to serve. The increase in silicon complexity and integration has imposed demanding requirements on packaging technology for higher I/O counts, finer lead pitch, enhanced heat dissipation, and high‐speed, reliable interconnects. At the same time, the industry is also driving toward reduced printed‐circuit‐board area and complexity. From the traditional role of a protective mechanical enclosure, the modern package has been transformed into a sophisticated thermal and electrical management platform.
Recent advances in high‐frequency packaging indicate a migration from wirebond (where the chip or die is interconnected to the package only on the periphery of the die) to flip‐chip (where the die is interconnected to the package using the entire die area); and from ceramic to organic packages, with cartridge and multichip technologies emerging as key form factors.
The RF front‐end module is the core of the complex systems, and its integration poses a great challenge. Considering the characteristics of the RF modules, such as high performance up to 100 GHz; a large number of high‐performance discrete passive components, design flexibility, reconfigurable architecture, low power consumption, compactness, customized product, short time to market, and low cost, the system‐on package (SoP
) approach has emerged as the most effective means to provide a realistic integration solution as opposed to the system‐on‐chip (SoC
) solution. The strength of SoP
is based on multilayer technololgy using low‐cost and high‐performance materials.