September 1998
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A View from Weiner
Sharp has introduced a five-chip CSP made by stacking five dies one upon the other and packing them together in a single CSP. The package, which combines flash and SRAM memories, is reported to require only a third of the mounting space on a printed circuit board that is required by two conventional TSOP plastic packages-or half that of two single-layer CSPs.Micron technology has joined Advanced Micro Devices Inc. in supporting AMD's proposal to the JEDEC Committee for a standard footprint for fine pitch, BGA chip-scale packages. Fujitsu also supports this standard proposal. Sharp's next development effort for a stacked CSP will combine logic and memory.
PC Expo
The recent IPC Printed Circuits Expo and Japan Printed Circuits Association shows focused on high density interconnects and packaging. Nearly 150 Taiwanese interconnect makers attended the JPCA show and its international symposium, "Report on the Technology Roadmap for Advanced System Integration and Packaging." There were only a handful of Americans in attendance at the seminar.The need for rapid adoption of chip-scale packaging over the next three years, in products ranging from tele-communications to DVDs, was discussed. As LSI chips begin to show up, the term "multi-chip packaging" (rather than multi-chip module), will become commonplace.
Enthone-OMI has introduced a pair of "microvia dielectrics" for use in making build-up circuitry. Both are liquids. One is photodefinable, while the other is designed for use with lasers.
Ciba Specialty Chemicals has announced an alliance with DuPont. The companies will produce and market Ciba's new photo-formable permanent dielectric for build-up circuits in a dry film format.
Creo, a new Israeli company, introduced its laser direct, liquid resist imaging systems with 50 micron track capabilities at the IPC's PC Expo in Long Beach, and has moved quickly to launch its product in Asia. It was well positioned at the Hitachi-Seiko booth at the JPCA show in June. Creo spokesman said that Hitachi-Seiko has been appointed Creo's representative for southeast Asia. Virtually every stand at the JPCA show had a sign mentioning one type or another of array packaging, microvias and chip-scale packaging.
Asahi Chemical has started work on producing a PPE-coated copper foil. This is intended for use in forming build-up circuitry layers more stable than foil coated with conventional FR-4 epoxies. The new material offers lower moisture absorption and better electrical properties for communications circuitry.
Fujitsu Microelectronics is now licensing its patented Bump Chip Carrier (BCC) packaging technology.
Microvia Equipment and Processes
Equipment and processes for forming microvias are rapidly improving. New lasers for hole formation are sprouting up everywhere, with price tags of $350,000 to $700,000 or more per system. Takeuchi showed a new CO2 laser machine for forming microvias in build-up circuitry. The system was developed with Japan Victor Corp. Electro Scientific Industries (ESI) showed a new autoload system for its 5100 UV laser at its stand at the JPCA event. MaxEdge, a new Taiwanese PC board shop, has joined the parade and ordered an ESI laser to form microvias. The machine is due for September delivery.A plasma line to form vias can cost up to $1.2 million. This makes the cost of setting up a pilot line to produce a few test circuits rather pricey. One enterprising company, PhotoMachining, has set-up a microvia hole "drilling" service in New Hampshire and has already produced parts for more than twenty circuit fabricators.
The infrastructure in Taiwan is growing rapidly with nine firms spending $400 million to set up factories to produce HDIs and array substrates for packaging. DayShine is building a factory to produce 300,000 square meters of BGA substrates a month, a volume well beyond current demand in the area.
Suppliers are forming new alliances to develop, produce, and market materials for build-up circuitry. Ciba Specialty Chemicals announced one such alliance to offer a dry film photoresist that was designed to become a permanent dielectric layer in build-up circuitry.
New reports indicate that shops in Taiwan will order 20-30 lasers this year for producing microvias for advanced packaging.
Mr. Weiner is Editor/Publisher of PAC/Asia Circuit News and a consultant to high technology companies. Contact him at 203.797.9103 or fax 203.797.9565.
www.weiner-intl.com