Microelectronics packaging: present and future

Spurred by the advent of low-cost, high-speed complementary metal-oxide semiconductor (CMOS) devices, the ever-increasing demand for faster, smaller and cheaper systems, and global competitive pressures, many fundamental changes are taking place in the microelectronics packaging industry to better prepare it to meet the challenges of the next millennium for systems ranging from consumer electronics to large systems such as mainframes. With CMOS performance approaching emitter-coupled logic (ECL), CMOS is emerging as the engine of systems that span the entire spectrum of the microelectronics industry, fading the demarkation lines between systems of different form factors, and encroaching on the territory of ECL-based mainframes. Partly due to the insatiable desire of society for lower-cost systems with high performance, the recent past has witnessed a shrinking large-system market and migration toward small systems, as reflected by the widespread use of CMOS-based personal systems and portables today. Also evident is the convergence of computers, radios, phones and videos into one low-cost portable multimedia system possessing eventually all the functions of these equipment to more fully exploit the senses of mankind. Moreover, much attention is being given to thermal/power management and development of low-power submicron CMOS chips even for small systems such as personal computers in response to the rising power dissipation associated with high-speed CMOS integrated circuits, and the demand for more energy-efficient and environmentally correct systems. To tackle these changes mandating high speed, low cost, portability and low power dissipation, packaging needs to take on an evolutionary track for cost-effective solutions based on a plethora of package options in existence today, particularly in the areas of enabling technologies such as high-input/output (I/O) connectors (e.g., flip chip, tape automated bonding, ball grid arrays and flexible edge connectors), multichip module (MCM) packaging (involving, for example, organic cards and both ceramic and silicon-on-silicon MCMs), high-wiring-capacity organic laminates, as well as efficient heat-sinking. This article reviews the present and the future of these enabling packaging technologies. all favoring a high level of package integration, maximizing the benefits of integrated circuit (IC) performance gains through reducing packaging delays, and small package form factors.