Steve Anderson on IC Package Assembly
Will the explosion in telecom add new players to the ranks of IC assemblers-or result in consolidation? According to market research firms such as IC Insights and Dataquest, the explosion in telecom is resulting in consolidation of suppliers for key components like DSPs as well as the addition of new suppliers for RF components-which are especially critical for the huge growth of wireless devices and applications. The market entry of new device manufacturers, who specialize in large niche markets, is increasing the need for more specialized IC packaging and the requirement for more engineering assistance from the packaging foundries. The major IC assembly companies today are going public to ensure better access to the financial markets that will help fuel their growth as they support the outsourcing trend. We also could see some new IC assemblers involved in the manufacture of modules targeted for portable products. Do you anticipate much impact from lead-free movements? The impact to IC assemblers will depend on what their customers-the IC manufacturers and the equipment makers-require. It is likely that Japan will be the first to legislate the requirement that equipment manufacturers recover lead in obsolete products, as part of a new household electric appliance recycling law scheduled to go into effect next year. The impact to assemblers will likely require that packages be made more robust to withstand a higher SMT peak soldering temperature of 260oC. This change is forcing a review of improved epoxies that will reduce the chance of "popcorning" and cracking. Additionally, BGA and CSP substrates may change to eliminate halogens and other toxic materials. Assemblers may have to requalify existing BGA and CSP packages with these modified substrates. Finally, the lead plating or ball composition and solder paste employed to attach the IC packages to the system board will have to be requalified and re-tested with materials that eliminate lead. How dense can packages become and still employ wire bonding? The limits of wire bonding are continually pushed with each new die lithography reduction and resulting die shrink or increase in die interconnection density. Bonding pad pitch or spacing is continuing to decrease and should reach 25-30 µm at the 0.10 µm lithography technology node. It appears that most wire bonding equipment suppliers will need fine-pitch capability at the proper time. Performance issues, particularly for wireless and high-speed applications, is forcing a segment of products into flip-chip to achieve the shorter interconnection path. As a result of the increased use of laser via drilling, we expect to see BGA and CSP substrates that are much denser. Laser drilling should also extend the life of wire-bonded packages. It seems that every packaging foundry wants to offer flip-chip assembly. What are the costs of entrance? The major costs of providing flip-chip assembly are high-volume bumping and redistribution manufacturing capability tightly coupled to IC dense substrate design capability and tools. Additionally, accurate manufacturing placement and underfill capability (especially for non-eutectic joints) is needed. Finally-and significantly, highly trained, experienced personnel are mandatory. The ability to scale up for large volume while managing cost reductions is imperative for this technology to become effective in an increasingly consumer-driven market. According to Jan Vardeman of TechSearch International, "If you're talking about flip-chip-on-board (FCOB), the major barrier is the known-good die issue. Because the bare die attached to the PC board must be underfilled, and commercial underfills are not available, there is also a concern about repairability," Vardeman maintains. Flip-chip-in-package (FCIP) is in widespread use, both for high I/O products, such as microprocessor, ASICS and DSPs and for low-end products where form factor drives FCIP use, Vardeman notes. Do you expect the rankings of IC packaging foundries to be the same two years from now? The rankings for 2000 are very similar for Amkor, with a market share of >25% with the next market share grouping of 1% to 15%. Based on the latest report from Electronic Trend Publications, it appears that the rankings have not dramatically changed. The aggressive advent of newer technology may pose challenges to those assemblers that are not able to finance and hire the experts necessary for the packaging customization we see appearing today. Onshore assembly, with few exceptions, has not been successful. Is it still viable? Offshore assembly is so entrenched with such an established infrastructure and wage structure that it is difficult for U.S.-based assembly firms to be competitive. There are certainly opportunities for small, rapid-turn prototyping centers that can test new technologies to resolve customer issues before large-scale volumes are required. Also, as the system-in-package or module direction becomes clear, there may be opportunities to perform low-volume quickturn assembly. What is the major driver for new IC assembly equipment? The major driver is flip-chip packaging, for both attachment, underfill, basic bumping and redistribution processing lines. We will see 300 mm wafer sizes driving a new generation of wafer saws, backgrinding equipment, wafer probing and mapping handlers, die attach systems and wire and flip-chip bonders. Those assemblers that also provide wafer bumping will have to retrofit or add new lines to handle 300 mm diameter wafers. How will the growth of wafer-level packaging affect IC assemblers? Last year, only 5.5% of all CSP production was wafer-level packaging (WLP). By 2002, it is expected to drop to 2%. Nevertheless, it appears to be too early to tell what long-term impact WLP will have on the IC assembly model. We see WLP as a natural extension to the CSPs we are now producing, albeit with different materials. As wafer-bumping capability develops at the IC assemblers, WLP will be another format available to customers. In the future, WLP will be produced on the bumping line and will have access to the same wafer testing and mapping capabilities that will exist for flip-chip packaging. Many IC assemblers will likely see this as another technology that can produce standalone packages or be integrated into system-in-package or modules. |
