Issue

10^thAnniversary
Anniversary Insights

01/01/2002

Packaging becomes a critical process

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BY AJAY P. MALSHE

Today's artificially intelligent systems are fabricated using sub-micron scale devices in micro- and meso-scale packages, primarily using electronic signals and the logic of programming to interface to the macroscopic world. The progress in this arena began in the 1950s with the invention and commercialization of the silicon transistor. Over the years, the packaging of these devices, which started out as an "afterthought" processing step to protect the device and connect it to the outside world, ultimately created its own standards and an industry unto itself

"Ancient" History

The current technology in advanced packaging makes it easy to forget how elementary much of the packaging process was, even just 10 years ago. At that time, many packaging "engineers" did not have engineering educations or backgrounds. Package engineering mostly consisted of package selection and then fighting fires when something didn't work.

At that time, familiarity with a set of products and problem-solving skills were often sufficient, largely because the device technology for most products had not reached the performance levels where the electrical and thermal behavior of a package (or its size) had a significant impact on the system performance. With more heat being generated now, however, and higher switching speeds, the package has become an integral part of the device technology. A recent surge in wafer-level packaging has made it clear how the packaging cannot be considered separately from the device. Wafer-level packaging processes make the package unequivocally part of the device: The chip can't be thrown over the wall to the packaging group if the packaging is done in the wafer fab.

The Demands of an Evolving Market

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So where will this trend take the packaging industry? With the advent of a new type of economy in which the next product must steal the market of the earlier version to maintain leadership, application-specific soft features of products - along with fast, dense and inexpensive traits - became the guidelines for designing next-generation electronic products. These guidelines implicitly result in three key features for the next generation application-specific systems-on-chip (SOC) or systems-on-package (SOP): mixed signals, mixed environmental domains, and varying scales of devices and packaging components. The collision of all of these variables makes the packaging an even more critical part of the device.

During the past few decades, various research laboratories and corporations around the world have been busy researching and developing novel devices, such as microelectromechanical systems (MEMS), with an ultimate goal of combining microelectronics, nanotechnology, biotechnology, optics - you name it - to enable arbitrary functionality in a single chip or a package. For the packaging community, this progress poses new development and manufacturing challenges for integrating mixed signals (electrical, optical, chemical, neural, magnetic, acoustic), mixed ambient domains (vacuum, hermetic, aqueous, optical), and - last but not the least - various sizes and shapes of devices.

These new developments only add to what needs to be juggled by the packaging engineer. Such professionals must be more multi-faceted than ever. The challenges faced by the packaging industry will continue to increase in a range of technical and non-technical fields, such as dicing, releasing, handling, interconnection, by-product management, materials, manufacturing processes, methods for reliability testing, modeling and simulation techniques, standards, professional development of today's packaging community, and of course, interdisciplinary and integrated education at universities to foster a new set of leaders in packaging technology.

The Future?

Success in these domains will result in allowing application-specific system and product designers to deliver next-generation engineered systems with novel features, such as self-organization for new interfaces, self-repair, self-powering, multifunctionality and reconfigurability, on demand information-to-knowledge conversion, and devices that are surely heading in the direction of "bio-mimetic packaging." The next 10 years should be even more dynamic than the last.