2001 Semiconductor Packaging and Assembly Outlook.

Future looks bright for BGAs, CSPs and wafer-level packages.

With slower growth projected for 2001, compared to the rapid growth in the electronics industry last year, companies are concerned that shipments of emerging packages might not meet expectations. Yet, while the rate adoption of some emerging packages might slow slightly, many applications will continue the expanded use of ball grid arrays (BGAs), chip-scale packages (CSPs) and wafer-level packages.

Ball Grid Arrays

In 2001, more than 1.6 billion BGA packages of all types will be shipped. Ceramic ball grid array (CBGA) and ceramic column grid array (CCGA) packages remain common for exceptionally high pin count application specific integrated circuits (ASICs) and processors. Shipping in high volume is the 1,657-ball CCGA for workstation/servers and network system products. The package has a 42.5-mm x 42.5-mm body size and a 1.0-mm column grid array pitch. Tape ball grid array (TBGA) packages, mainly with wire bond interconnects, continue to ship for many computer, telecommunications and network systems.

The largest volume shipments are the plastic BGA (PBGA) packages, and personal computers (PCs) remain the largest volume application. While PC sales are slowing, the typical box will still contain three to five PBGAs. Intel has long moved its chip set designs from plastic quad flat packages (PQFPs) to PBGAs--many pin counts are in excess of 500 I/Os. Graphics and video chips are increasingly packaged in PBGAs.

Changes continue to take place in CPU packaging. While CBGA shipments have been common for several years, Motorola has introduced some members of its PowerPC family in PBGAs, including the MPC745, the MPC755 and the MPC7410. While some of Intel's CPUs are still shipping in an organic land grid array (OLGA) package with solder balls, the majority of new Pentium shipments are supplied in plastic pin grid arrays (PPGAs) as a result of demand for socketable processors.

Perhaps the PC's greatest future rival is the game machine, and PBGAs are no exception for the high pin count devices in these systems. Sony's popular PlayStation 2 contains an Emotion Engine processor packaged in a 540-ball PBGA with a 42.5-mm x 42.5-mm body size and a 1.27-mm solder ball pitch. The graphic chip is also packaged in a PBGA.

A variety of PBGA pin counts can be found in workstation/servers, telecommunications and network system products. While shipments of network systems may not see the same growth rate as last year, as a result of the demise of many dot.coms, BGA package shipments are expected to see continued growth. Fast static random access memory (SRAMs) are supplied in PBGAs in high volume. High pin count designs from ASIC makers continue to ship in BGAs. Cisco's boards are populated with TBGAs, CBGAS and PBGAs--increasingly high pin counts are common. Sun Microsystems has some of the highest pin count PBGA packages, one of which has 1,848 balls with flip chip inside.

Flip Chip Expansion

Flip chip is increasingly the interconnect method of choice for high performance ASICs. More than half the BGAs used by Sun Microsystems this year will be flip chip inside, and, in five years, 90 percent of Sun's BGAs will be flip chip. Flip chip is also finding its way into the interconnect realm previously dominated by wire bond. The potential expansion of flip chip technology into the midrange pin counts represents a shift in the adoption of the technology as well as a maturing of the industry. A recent example is the introduction of LSI Logic's flip chip package targeted at applications with between 300 and 1,150 leads that require higher electrical and thermal performance than that offered by wire-bonded packages.

Flip chip interconnect is found in high volume within the PC market in the form of flip chip in package (FCIP). For several years, microprocessor speeds have required the use of flip chip interconnect to achieve the performance specifications designed into silicon. FCIPs include products such as AMD's processor family, Intel's Pentium products, Motorola's PowerPCs and the new Transmetta microprocessor. In the near future, chip sets are also expected to use flip chip as the interconnect method inside the package.

Another new development is the proliferation of bumps for small die (less than 2 mm x 2 mm), some times considered wafer-level packages. Both of these developments represent not only improvements in flip chip infrastructure, but also cost reductions in the technology. [1]

Chip-Scale Packages

While many mobile phone makers have revised handset shipments downward for 2001, this segment remains the highest volume application for all types of CSPs. In 2001, more than 5 billion CSPs are expected to ship. Some of the highest volume packages are the stacked packages--typically with one flash memory and one SRAM. These packages use either tape or laminate substrates. Shipments of CSPs with more than two stacked devices, as well as stacked CSPs, will move into volume production this year.

Digital signal processors (DSPs) from Texas Instruments, supplied in a flex-based CSP, continue in high volume use, with mobile phones as a major application. Laminate-based CSPs, especially in molded strips, will also increase in unit volumes this year. The high volume of lead frame-based CSPs, such as Amkor Technology's MicroLeadFrame (MLF), Fujitsu's bump chip carrier (BCC) and quad flat no-lead (QFNs) from a variety of companies, may come as a surprise to many industry observers. These low lead count packages, without solder balls, are inexpensive to manufacturer and are easy to mount. Some ceramic-based CSPs are also shipping in mobile phones and several Japanese consumer products.

Third and fourth generation digital cameras and camcorders will continue to ship with CSPs--making extreme miniaturization possible. Flash memory for memory cards, as well as mobile phones, continues to be a volume CSP application.

Wafer-Level Packages

Devices packaged at the wafer level, with or without bumps (sometimes considered flip chip), continue to grow for a variety of products, including integrated passives, controllers, memory and other low pin count devices with less than 100 I/Os. Although too small in size to be meaningful individually, these devices are anticipated to count for more than 140,000 8-inch equivalent wafers this year. Popular packages include JEP Technologies' RealCSP and Fujitsu's SuperCSP--shipping in at least two different Casio watch modules. Dallas Semiconductor's bumped wafer-level packages continue to ship in volume for a number of applications. National Semiconductor's voltage regulators, controllers and op amp devices are expected to ramp this year, shipping in the micro surface-mount device (SMD). Shell Case, with its new licensee in Taiwan, and FormFactor, with its license to Infineon, will both see increased production. Whether called a wafer-level package or a bumped die, shipments from Flip Chip Technologies have gr own dramatically, and the company is now operating at full capacity--licensees will soon come on-line to share the increase in demand. Increased volumes are also expected for Unitive's Xtreme CSP.

Traditional Leaded Packages--Often Forgotten, Not Gone

Leaded packages such as quad flat packs (QFPs) and thin small outline packages (TSOPs) continue to ship in billions of units. These packages may not decline in volume, only in margin. For many applications, these packages remain the workhorse of the industry.

Outlook for 2001

Despite a slowing economy, unit volumes for integrated circuits will continue to grow this year. [2] Many new IC designs will ship in emerging packages such as BGAs and CSPs. Most new ASIC designs will ship in BGAs. Memory devices such as flash, SRAM, and some high speed DRAM are increasingly supplied in CSPs. With cost reduction as a continuing theme, efforts to package at the wafer level will continue.

E. Jan Vardaman is president of TechSearch International, Austin, TX.

References

(1.) Electronics News Online, Thursday, January 25, 2001.

(2.) The McClean Report, 2001 Edition, IC Insights, p. 2-28.