Issue



Nanos Are Coming


03/01/2006







By George A. Riley, contributing editor

It’s official - the nanos are coming. While not yet battering our packaging gates, they are within sight of our walls, and advancing rapidly. Within 3 to 5 years they’ll be in our streets, or perhaps sitting behind our desks. A sure sign of the looming change is that some packaging engineers are already in deep denial, frightened by a nightmare future where organic chemistry makes metal (and their engineering skills) obsolete.

The alarm came from SEMI in their December 14, 2005, webcast, “Global Nanoelectronics Markets and Opportunities.” Their well-researched forecast makes clear both the major changes that nanotechnology will bring to electronics packaging, and how soon we will see those changes. SEMI reports the 2004 worldwide market for nanoelectronic materials and equipment at $1,448 million, and forecasts a 20% compounded growth rate to $4,219 million in 2010.

SEMI predicts that nanotechnology-based electronic product introductions will begin within 3 to 5 years. The leading electronics applications will be in displays, disk storage, MEMS/NEMS, optoelectronics/sensors, and semiconductors. All of those will require suitable, possibly innovative, packaging. In addition to the extensive market research supporting the report, there are at least three external forces buttressing its conclusions: major corporate activities, nanotechnology benefits, and rising public opposition.

Behind the SEMI forecast is a growing drumbeat of corporate activity as innovative packaging-related companies establish their strong points early. On December 5, 2005, Fujitsu announced they have demonstrated growing carbon nanotubes as heatsinks on semiconductor wafers. The higher thermal conductivity of nanotubes permits high power RF die to be flip chip-mounted, previously impossible because solder bumps could not dissipate the heat. Flip chip eliminates bond wire inductance, allowing higher frequency operation. The combination of nanotubes and flip chip makes higher power, higher frequency RF amplifiers feasible. Fujitsu expects to have these nanotube heatsink power amplifiers available for mobile phone base stations in about 3 years.

Fujitsu is only one of many major electronics packaging-related innovators. Earlier in 2005, Hewlett-Packard announced laboratory versions of nanoscale crossbar switches, a possible alternative to conventional logic. SUSS MicroTec is offering nanoimprint lithography systems. Samsung began a joint development with the Korea Advanced Institute of Science for memory chips thinner than 50 nm. In 2004, Toshiba announced that the addition of nanoparticles to conductive silver epoxy provided a die-mount adhesive with better properties than either solder or conventional silver-flake adhesive.1

These product developments all directly affect packaging. Future products like nanotube field effect displays, organic semiconductors, and similar developments will no doubt bring their own packaging challenges. The compelling benefits of nanotechnology, such as higher thermal and electrical conductivity, greater mechanical strength, lower melting points, self-linking metal conductors, and altered adhesive properties, make its early use in microelectronics packaging inevitable.2

Industry generals have positioned electronics well for the nanotechnology invasion, but not all of the troops are following.3 At one recent IMAPS regional meeting, a “future trends” presentation included nanotechnology among the growing influences on advanced packaging. During the question period, a small but vocal group of status-quo defenders insisted that nanotechnology has no place in electronics packaging. Their war-cry was, “It’s all hype.”

This defensive response is sometimes instinctive in our industry. Conservative engineering says “Don’t change anything unless you have to - and then change as little as possible.” The same spirit that once motivated some layout experts to resist CAD systems and some production managers to ignore surface mount assembly now faces the nanotechnology threat. If chemists and the like are going to dominate creating new packaging, where will electronics engineers fit in? But to assume that no packaging companies will race to embrace the latest technical innovations is to ignore both history and today’s market realities. Nanotechnology is on the march. We can either open the packaging gates and welcome the troops, or risk having the gates battered down upon us.

References

  1. Yasunari Ukita, et al., “Lead-free Die-mount Adhesive using Silver Nanoparticles applied to Power Discrete Package,” IMAPS 2004, Long Beach, California, November 2004.
  2. Alan Rae, “Nanotechnology and Low-temperature Electronics Assembly,” SMTA Pan-Pacific Microelectronics Symposium, Kauai, Hawaii, January 2005.
  3. David Forman, “Electronics Takes the Lead,” Small Times, March 2005, pp. 18 - 22.

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GEORGE A. RILEY, Ph.D., Advanced Packaging contributing editor, may be contacted at Flip Chips Dot Com, 210 Park Ave. #300, Worcester, MA 01609; 508/753-3752; E-mail: griley@flipchips.com.