Future packaging - trends in microelectronic packaging
Lee Smith, Vice President of Laminate Business Development at Amkor Technology, Arizona, USA, describes the microelectronic packaging market.
There was little good news in the last quarter regarding the worldwide economy, consumer spending, the electronics industries or employment. Industry analysts forecast electronic equipment and semiconductor revenues will retract throughout 2009, followed by a strong rebound in 2010. The only other time that electronic equipment revenues declined was in 2001 and 2002 due to the dot com and ‘millennium bug’ inflated inventory crashes.
However, the semiconductor market has been more cyclical with a drop in sales every five years since 1975, and now – due to major sales declines – 2008 dropped by between two and four per cent from 2007 revenues. The chart below shows the Semiconductor Industry Association’s forecast through 2011, where it projects a 5.6% decline for 2009. What the declining growth rate from the 2004 peak masks, is that from 2002 to 2007 the industry grew strongly.
Nevertheless, the industry faces major economic challenges as average selling prices have continued to decline in the past decade.
SEMI Europe, the industry association serving the manufacturing supply chains for the microelectronic, display and photovoltaic industries, presented a White Paper to EU officials stating that half a million jobs could be at risk in the European semiconductor industry without additional public investment. This situation could scare job seekers, students and new graduates away from a career in the sector. However, three key points need to be considered –
• The more dramatic the changes, the greater the opportunities.
• The world is increasingly reliant on electronic equipment, with personal computers and mobile phones representing nearly 60% of overall semiconductor consumption. The growth of these products remains strong in developing regions and 2010 replacement rate rebounds are expected in mature markets. Therefore, any downturn in demand is typically short, followed by a strong market recovery or rebound.
• Microelectronic packaging is increasingly critical to semiconductors, creating new opportunities.
Packaging in the semiconductor industry is the microelectronic assembly processes and technologies that produce finished components from incoming semiconductor wafers. The package protects the chip and translates the terminal pads from the submicrometre integrated circuit density to the courser printed wiring board interconnect densities in an electronic system. What is inside the package is becoming increasingly complex.
In September 2008, before the downturn in demand, it was estimated in a Gartner Research, USA, report that the 2008 worldwide electronic equipment market would generate revenues in excess of US$1.4 trillion or 3.5% of worldwide GDP. It was forecasted that semiconductor devices would grow four per cent to US$285 billion, roughly 20% of electronic equipment value. The microelectronic packaging value (including testing) was estimated to be over US$49bln, approximately 17% of the semiconductor value.
The report highlights that the value of microelectronics is growing more than twice as fast as the overall semiconductor industry, as devices and systems require more advanced packaging technologies, accounting for 19% of the semiconductor value by 2012.
Application specific packaging
Just as semiconductor integrated circuits have become more application specific devices through the use of system on a chip (SoC), microelectronic packages have moved to application specific technologies that meet both semiconductor and electronic equipment (system) requirements. This trend has become more critical as consumers drive electronic equipment features, functions and market price. Equipment designers increasingly look to semiconductors as the most cost effective way to boost functionality. This is due to the economics of semiconductor scaling known as Moore’s Law.
For nearly 40 years the Law has accurately predicted the number of transistors on a chip will double approximately every two years with the introduction of each new laboratory technology node. The doubling of transistors gives a 40% reduction in chip costs meaning lower semiconductor prices.
However, huge investments are needed because the cost of building a new semiconductor laboratory has increased 250% to US$4.5bln of investment projected for 2010. The cost of developing a new central processing unit has also increased 400% over the last 10 years. This has resulted in semiconductor makers attempting to make multi-chip packaging technologies like system in a package and 3D or stacked packaging technologies to integrate higher functionality and memory content rather than rely on SoC approaches. The International Technology Roadmap for Semiconductors called this post-complemantary metal oxide semiconductor era as ‘More than Moore’.
Packaging technologies do not have the benefit of scaling because of the limitations associated with package assembly processes and materials. Packaging technologies require a large content of commodity materials, including copper, gold, silver and petrochemicals, which have risen in price as demand exceeds supply. As a result, achieving a low packaging cost at an optimum performance level remains difficult for design, development and through the package lifecycle.
The requirements include area and thickness reduction, maximising die size and supporting both wire bond and flip chip first level interconnects (die terminals to package substrate), higher semiconductor integration, and higher lead counts at finer lead pitch, with challenging thermal, electrical and mechanical performance.
Package technology platforms incorporate ceramic, hermetic, leadframe, laminate and wafer level processed, single chip, multi-chip, 2D and 3D, along with passive components, such as radio frequency, analog, digital, mixed signal, optical, discrete and micro-electro-mechanical systems devices.
As package applications, requirements and technologies become more complex, their development and manufacturing require more specialised technical expertise.