The SOP for miniaturized, mixed-signal computing, communication, and consumer systems of the next decade

From cell phones to biomedical systems, modern life is inexorably dependent on the complex convergence of technologies into stand-alone products designed to provide a complete solution in small, highly integrated systems with computing, communication, biomedical and consumer functions. The concept of system-on-package (SOP) originated in the mid-1990s at the NSF-funded Packaging Research Center at the Georgia Institute of Technology. This can be thought of as a conceptual paradigm in which the package, and not the bulky board, as the system and the package provides all the system functions in one single module, not as an assemblage of discrete components to be connected together, but as a continuous merging of various integrated thin film technologies in a small package. In the SOP concept, this is accomplished by codesign and fabrication of digital, optical, RF and sensor functions in both IC and the package, thus distinguishing between what function is accomplished best at IC level and at package level. In this paradigm, ICs are viewed as being best for transistor density while the package is viewed as being best for RF, optical and certain digital-function integration. The SOP concept is demonstrated for a conceptual broad-band system called an intelligent network communicator (INC). Its testbed acts as both a leading-edge research and teaching platform in which students, faculty, research scientists, and member companies evaluate the validity of SOP technology from design to fabrication to integration, test, cost and reliability. The testbed explores optical bit stream switching up to 100 GHz, digital signals up to 5-20 GHz, decoupling capacitor integration concepts to reduce simultaneous switching noise of power beyond 100 W/chip, design, modeling and fabrication of embedded components for RF, microwave, and millimeter wave applications up to 60 GHz. This article reviews a number of SOP technologies which have been developed and integrated into SOP test bed. These are: 1) convergent SOP-based INC system design and architecture, 2) digital SOP and its fabrication for signal and power integrity, 3) optical SOP fabrication with embedded actives and passives, 4) RF SOP for high Q-embedded inductors, filters and other RF components, 5) mixed signal electrical- test, 6) mixed signal reliability, and 7) demonstration of SOP by INC prototype system.