By Jeff Karoub
Small Times Staff Writer
HANNOVER, Germany, April 17, 2002 — Yelling “stop the presses!” when a newspaper is being printed means something is wrong, but a German firm said its process of halting production to package parts could help move MEMS in the right direction.
MicroTEC has launched 3-D Chip-Size Packaging. 3D-CSP combines packaging and housing into one system: It lets fabricators stop at any point in the process, integrate parts, then resume production — allowing the parts to be protected from the environment.
“(Our) technologies realize production without any tooling — it’s direct from computer-
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| 301 companies exhibit a diverse array of applications for microsystems at Hannover Fair 2002 |
Though it’s not part of many sales pitches in the halls of Hannover, packaging is important for MEMS development, since it often proves to be a major bottleneck to production. Not only must microscale mechanical, electronic and optical parts be integrated into a package that protects them from the environment, but the package must also allow for those parts to interact with the environment.
The one-size-fits-all packaging approach for integrated circuits doesn’t work for MEMS because of their diverse shapes, sizes, strengths and functions. The packaging needs of a biochip, for instance, differ from those of an optical switch.
“The packaging is just as customized as the device, by and large — it’s not a cookie-cutter solution,” said Marlene Bourne, a MEMS analyst for In-Stat/MDR who is attending the fair.
“You can have a standard MEMS accelerometer, but the differentiation is going to be the packaging. That’s where the road bump is.”
Reinhardt said microTEC’s 3D-CSP process accounts for many of those differences, meeting customers’ requirements at an earlier stage of development. “The future will be dominated more and more by customer specific production,” she said. “This technology is ready for integrating fast-changing needs.”
Although no product is yet on the market, 3D-CSP will first be used in a blood micropump being developed by the German firm Empella. MicroTEC will integrate a pressure sensor into the device, which will be used in heart surgeries.
Christine Neuy, chief executive of IVAM, a German microsystems trade association, said the interesting part of microTEC’s work is the process of creating cavities, inserting the parts, then growing the polymer material to cover the cavities.
“It’s a generative technology — you don’t remove material but you generate layers,” she said. “You create those layers step by step.”
She said that technique might create roughness from one layer to the next, which could be less desirable for microfluidics or other devices that require smooth walls and sides. “It depends on the application, as it often does in microtechnology.” For its part, microTEC said it has managed to get rough surfaces down to the nanoscale.
Packaging expert Marc Waelti agreed that there will be some limitations to its application, but microTEC’s process represents a step forward for complex, hybrid microsystems.
“Co-integrating different types of devices, such as fluidics, electronics and optics is very difficult to do, and this is an elegant way to do it,” said Waelti, manager of packaging and assembly at Corning IntelliSense, which also is an exhibitor in the MicroTechnology portion of Hannover Fair. Corning IntelliSense’s prototype-to-production services include a range of packaging processes, but none compete with microTEC, Waelti said.
Wafer-level packaging is by no means unique to microTEC, but the firm is achieving a higher level of precision through its laser technology, according to Robert Mehalso, a speaker at Hannover Fair and founder of Microtec Associates, a similarly named but unrelated U.S. firm.
“It’s of interest for low-volume, specialized production,” Mehalso said. “People want customization. This might give them the opportunity for customization at a reasonable cost.”
Wolfgang Ehrfeld, a professor, pioneer and force for the growth of microsystems in Germany, founded Ehrfeld Mikrotechnik AG in 2000 with his wife, Ursula.
Ehrfeld said packaging and integration is extremely important for his company and the industry. He said his firm, which bills itself as a “one-stop shop for microtechnology” services and products, also employs wafer-level packaging approaches because boosting intelligent packaging is the best way to reduce costs.
Still, he doesn’t promote the processes because he doesn’t believe the topic resonates with customers.
“I do not want to buy packaging; I want to buy a product,” said Ehrfeld, who also formed the Mainz Institute of Microtechnology a decade ago with his wife. “Our customers are not interested in how we fabricate. They want to know the technical element works, it is resistant to corrosion and what it costs. They’re not interested in how we make it.”
More news from Hannover Fair 2002
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