HDI Circuits Abound at Japan Printed Circuit Association Show

The June Japan Printed Circuit Association (JPCA) show, held in Tokyo, showed more enabling innovations and improvements for the packaging infrastructure than any other printed circuit focused exhibit that I have attended.

High-density build-up circuits abounded, so did an almost bewildering variety of processes and technologies for their construction, ranging from plating, to vacuum deposition, to coating, or filling and curing. A number of these require "unique" design rules.

Ibiden was reported to have spent well over $100 million to establish its processes and production lines and is reported to have the highest yield rates of all.

Taiwan is rushing to catch up and position itself in time for the expected transition in future orders to the HDI business. The island, which had a handful of laser drills a year ago, now has about 40 in operation, with more on the way. A few firms say they have had help from Intel, while others have obtained help in Japan.

Some of the printed circuit fabrication equipment displayed employed technology borrowed from the semiconductor industry to accommodate the shrinking feature sizes of printed wiring. For example, Ushio displayed a stepper exposure system with a >175- mm (7-inch) quartz mask and an exposure area >200 mm. The machine demonstrated the exposure of a 16-mp (16 circuits per 450-mm x 600-mm panel) pattern.

Asahi Optical, ETEC Systems and Orbotech demonstrated direct exposure systems with 50-micron resolving capabilities. The Orbotech system was mated to an Amtech autoload/unload system. The Japanese firms that made CO2 lasers for forming microvias in substrates have all added Yag UV lasers to their arsenals. Chiyoda showed a pulsed-current power supply for electroplating blind microvias.

Materials and process innovators were not to be outdone. Sony Chemical introduced "MOSAIC," a bump-bonded multilayer flexible circuit. Asahi Chemical and Nichigo Morton introduced dry film photoresists with resolving capabilities of 8 microns (0.3 mil). Mitsui Mining and Smelting showed a new 3-mm copper foil (on a copper carrier layer) for HDI circuitry. The thin foil can be "pierced" by a CO2 laser.

Not seen was JME's new conductive cyanate-ester compound, which was introduced in Boston during NEPCON East. Another new product introduction was DuPont's Riston Goldmaster primary-imaging dry film photoresist for the difficult Ni/AU plating challenges of boards for wire bonding applications.

There was a dearth of Americans and Europeans at the Tokyo event. I saw only one U.S. fabricator wending his way through the show.

There were, however, about 180 Taiwanese fabricators exploring the exhibit, as well as a number of Koreans. One Korean fabricator stated that he "doesn't even look at boards under 10 layers," and that he is rapidly expanding his HDI capability for customers Cisco and Lucent. He views this activity as a requirement, not an option, for future survival as HDI multilayers and silicon platforms continue to converge.

Companies within the telecom industry, e.g., Nortel, continue the trend in outsourcing to assemblers as well as fabricators. New designs for flip chip on six- and eight-layer HDI boards are showing up in Southeast Asian shops.

Flip chip is rapidly increasing in acceptance and use as a manufacturing technology of choice. Just a few months ago, Amkor technology opened its U.S. Flip-Chip Development Center in Chandler, Arizona. The company reported that it is already developing flip-chip solutions for 10 IC manufacturers.

The Dii Group has been awarded a huge multiyear telecom contract in China. Dii is continuing to expand its Zhuhai campus with more than a dozen surface mount assembly lines in operation. The Group will become one of the first in mainland China to offer laser microvia and HDI formation in its PC board facilities.