TOKYO – JPCA 2007, while held in the middle of a slowdown in the electronics interconnect industry, must be considered an unqualified success. Between the innovations on display, the incorporation of the Protec assembly show, and real world collaboration, JPCA demonstrated the possibilities of realizing technical advances, and building the foundations for growth while maintaining profitability.

There were fewer than 200 Westerners in attendance at a show that was packed for all three days. As the Western industry flails, the East rises.

Overall, the printed circuit fabrication industry has continued its consolidation. While sales revenues and volumes grow, resources and technology are concentrating in fewer hands, and margins decrease as technology matures. There is much greater focus on “bang for the buck."

Booth sizes for many exhibitors were shrunk and fewer systems were displayed. However, that which was exhibited hinted at the still amazing possibilities of an industry fundamental to modern society. It’s not getting any easier, but the technologies are available, whether in high density interconnect, embedded components, or yield and process improvement. I saw examples of 30 micron lines and spaces; stacked and staggered vias, embedded actives and passive components; all in production in products used everyday all over the world.

Starting with laminates, dimensional stability is improving; lower dielectric constants, thermal resistance, and compatibility with extended chemical and mechanical stress are all at the forefront. Several papers during the technical program, and emphasis on the show floor, were on reducing copper foil thickness along with surface preparation for ultra-fine-line applications.

In drilling, resistance to cracking during laser drilling, 200,000 rpm spindles becoming a standard, and the ability to drill higher stacks with better feeds and speeds are all part of a dynamic improvement in performance. Drill room monitoring has become standard at many companies. The ability to use real-time measurement of feeds, speeds, and drill wander improves yields and productivity considerably, with several manufacturers offering the technology.

In photoresists, the drive toward finer lines with improved sidewall quality has shown incremental improvements. Dry-film remains standard in Japan, but several suppliers exhibited roller coaters and other liquid photoresist application technologies. In imaging, the emphasis was on hybrid direct imaging systems, with several manufacturers demonstrating conventional lamp technology based systems with the ability to write directly at production speeds with the benefits of scaling and artwork elimination. Interested in laser-based direct imaging systems was also strong. Remember: many Japanese PCB manufacturers have for years achieved high yields on fine lines. Today’s bleeding edge is 15 micron geometries. 50-75 micron lines and spaces are considered standard, with electrical tests yields in the low-to-mid 90th percentile. One interesting development in the layup process is to use prepreg as a rigidizer in certain designs.

The variety and scope of designs and technologies is truly amazing. Perhaps a dozen HDI processes, some proprietary, most collaborative, are helping the Japanese interconnect industry extend its dominance. Reduction in the real estate footprint, reduced trace lengths, better pad adhesion, superior heat dissipation, and reduced cost/functionality are all part of the package.

Indeed, there is a misconception in the West as to applications utilizing HDI. A recent flow chart by Matt Aoki published in the Printed Circuit Journal listed the usual cellular, handheld, digital camera, and other consumer applications. HDI is gaining significant market share in Japan in notebook computer, automotive navigation systems, workstation, broadcasting equipment and telecom base station products. Constructions include 1-2-1 four-layer boards, 1-4-1 six-layer boards, 2-4-2 eight-layer boards, and 4-12-4 20-layer boards. There is discussion of using HDI in Japanese coinage and railroad tickets as well. In other words, HDI is being implemented rapidly in every application imaginable. If its stronger, faster, lighter and less expensive, why not?

A major development seen at JPCA was the emergence of the EWLP initiative, which was advertised by a number of the exhibiting interconnect manufacturers. Billed by CMK as the next generation in system packaging technology, EWLP is a consortium that cuts across the component, interconnect, assembly, and OEM spectrum with the objective of implementing and standardizing embedded active components, specifically wafer-level packages. Participants include CMK, Ibiden, ST Micro, Omron, Denso, Kyocera, Amkor, Sony, Toppan, Murata and many others. With this process, the package is mounted directly onto the innerlayer. In one process, microvias with copper posts permit the wafer package to be connected directly to the circuits, which is said to offer much greater interconnect reliability when compared to wire bonding or solder. Shock and severe environment resistance are also improved significantly by embedding active components in the board. Circuit routing distances are reduced, and heat dissipation is reportedly also enhanced. Millions of products have shipped, including runner’s watches, digital television tuners, and mobile handsets. EWLP is a production reality, and is changing the identity and nature of the interconnect, opening up new vistas for designers and OEM’s.

Several interconnect manufacturers also noted the shorter product development cycles possible. The nature of EWLP will change the economic structure of electronics manufacturing. Today’s industry separates the PWB manufacturer from the assembler and, often, the OEM. The EMS industry has caused a fundamental disruption of the economics of the finished product. Low cost rules, and those who yank the supply chain the hardest win. EWLP requires high levels of technology, close cooperation throughout the chain from design to finished assembly, and higher margins at the interconnect manufacturer based upon increased functionality and reduced overall device cost. Those who adapt and innovate will have a bright future. Those who don’t are doomed to play the price game.

HDI and EWLP have a direct impact on test and inspection. The stakes are much higher as the overall value of the substrate increases. In the case of EWLP and buried passives, the devices are already tested, and many of them, especially 0201 resistors and capacitors, are simply the same ones once placed by chipshooters. Test equipment manufacturers are geared up. The fundamental test parameters haven’t changed significantly and the electrical values remain constant. In some ways, by freeing up real estate on the surface of the substrate, EWLP may actually help improve testability. HDI substrates require a high degree of precision, and impedance matching requires more precise test parameters.

In assembly, the emphasis is on the JISSO roadmap. The message of most major pick-and-place equipment manufacturers was 01005 placement and 0.04 mm pitch, common scalable platforms, and flexibility. Greater z-axis control through component height detection and substrate warpage detection were also advertised.

Nitrogen reflow systems were widely exhibited as a yield enhancement tool in Pb-free assembly. As elsewhere, greater system flexibility and rapid job changeover are the reality of production in Japan. Solder paste inspection, and chip and lead floating detection were emphasized at the booths of the test and inspection suppliers.

Technical papers were presented on the show floor, in many cases to overflow audiences. Approximately 175 presentations were delivered on topics ranging from semiconductor technology trends to the REACH waste initiative. A number of these were product presentations by suppliers, while most were less commercial. Many were related to specific applications such as automotive and digital mobile, or processes such as embedded components or optoelectronics. Printable circuits using ink jet technology was another topic receiving significant attention. The three-day show was simply not long enough to delve deeper into the possibilities of the interconnect.

As North American and European OEMs remove themselves further from the process and technology, they risk a loss of the means and understanding of production. With increased functionality and higher profit margins, the interconnect is not simply a commodity, but rather the foundation of the future. -- by Matt Holzmann, special to PCD& Holzmann is president of Christopher Associates, a large distributor of PCB and assembly equipment and materials.
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