Bosch raises the bar: microelectronic advances keep company on cutting edge

REUTLINGEN, Germany - You won't find Robert Bosch GmbH's microelectronics plant on any German tourism bureau lists of places to see, but it should be - at least if you have any interest in the future of automobiles.

With electronic controls responsible for more vehicle character and personality with each passing model year, where best to look into the automotive crystal ball than at one of the world's leading electronics suppliers' facilities?

Each year Bosch invites automotive journalists from around the world to Germany for a business and technological update. Reutlingen got the nod for the 52nd such gathering because executives say its microelectronics business is one of the company's strongest growth areas. And the continued expansion of the operation here is ample evidence of that statement.

The original Reutlingen plant opened in 1971 and was expanded in 1979. At that time semiconductors were produced exclusively to meet in-house automotive component needs. In 1995, a new semiconductor plant was built to meet growing internal demand for automotive components as well as information, communications and consumer goods. Bosch also produces application-specific components for the open market and, starting in 1997, for other semiconductor manufacturers.

"The new semiconductor plant was designed for a capacity of approximately 600 wafers per day," says Heiner Gutberlet, a member of Bosch's board of management. "The growing demand for components made it necessary to expand the production capacity to 800 wafers a day by late 1997." This expansion will cost $40 million (DM60 million).

Mr. Gutberlet says automotive equipment remains the best source of revenue in the Bosch empire, which spans power tools, appliances, telephone equipment, factory automation systems and packaging machinery. Automotive accounted for $7.3 billion (DM11 billion) in sales during the first half of 1996, 60% of the company's $12.3 billion (DM18.2 billion) worldwide sales during the period. The figures do not include revenue from the AlliedSignal Braking and e.1.m. Leblanc acquisitions.

Bosch intends to maintain its traditionally strong research and development efforts by upping its outlay for R&D from $1.6 billion (DM2.5 billion) in 1995 to $1.7 billion (DM2.6 billion) this year, adds Mr. Gutberlet.

This commitment to R&D - plus a track record that includes antilock braking, traction and vehicle dynamics control (VDC), electronic engine management and numerous other devices - paved the way for a batch of new Bosch product announcements.

One new product is a silicon-based, micromechanical VDC yaw-rate sensor that is smaller and almost 5 oz. (0.17 g) lighter than its steel-based electromagnetic predecessor. Other yaw sensors on the market are quartz-based. Bosch decided to leapfrog quartz and go right to silicon.

Norbert Rittmannsberger, executive vice president of Bosch's ABS, chassis and safety systems division, says he expects the new sensor to go into production in mid-1998.

"The core element of the new sensor is a silicon chip about 7 mm (0.27 ins.) square, approximately the size of a fingernail," says Mr. Rittmannsberger. "The conducting tracks of the sensor chips are so fine they can be seen only under a microscope at 50 times magnification."

The sensor element is etched directly into the silicon, explains Mr. Rittmannsberger. The acceleration sensor, the microprocessor and the surface-mounted components are arranged on one ceramic substratum and bonded with glass conductors to the metal base. The entire yaw-rate sensor is enclosed in a metal cover. Afterward it gets a plastic housing with an electric plug specific to the customer's application.

Bosch's expertise in microelectronics prompts Martin Zechnall, president of the company's semiconductor and electronic control unit (ECU) division, to claim that the German industrial giant is the first supplier of automotive ECUs produced with micro-hybrid technology. This technology, based on a special support material sintered together from several layers of flexible ceramic foil, makes further ECU miniaturization possible, he says.

"By the end of the century approximately 30% of all Bosch control units will be produced with this technology," Mr. Zechnall says. "The advantages are resistance to high temperature and vibration loads, combined with improved electromagnetic compatibility and reduced size."

Bosch also uses electronics to chip away at the size of its headlight systems. The company introduced its first Litronic high-intensity discharge (HID) low-beam headlights (combined with halogen high beams) with BMW in 1991 and continues to refine the product.

"In 1997 Bosch will introduce the third generation of Litronic and the HID Compact PES system," says Gunter Hege, senior manager of lighting systems. "And in 1998 we will unveil another breakthrough in automotive technology, the Bifunction Litronic HID, for one-bulb low- and high-beams."

The new Litronic cuts system volume and weight and integrates the HID's starter and connector into one component, and offers greater design flexibility, says Bosch, which reduced system ballast volume from 79 cu. ins. to 17 cu. ins. (1.301L to 0.281L) and mass from 70 oz. to 12 oz. (2 kg to 350 g) since the system's first generation.

HID Compact PES offers more light from smaller and more-compact headlamps, says Mr. Hege. The result is improved aerodynamics, packaging advantages and more design freedom. This development reduces the depth of Litronic headlamps to 5 ins. (128 mm) or 25% with almost the same luminous flux and range. The lens diameter was reduced from 2 ins. to 1.5 ins. (60 mm to 40 mm).

The Bifunction Litronic uses one discharge bulb and one reflector for both low- and high-beams. In a fraction of a second, the position of the discharge bulb in the reflector is changed electro-mechanically from the low-beam position to the high-beam and back.

Bosch also has developed a headlight leveling system for its HID applications in Europe. Such systems are mandated by regulation in Europe. It recognizes any movement of the car body and tracks headlamps accordingly with the aid of electrical motors. Special sensors for the angular movement at the front and rear axles detect not only static compression of the rear end of a loaded-trunk car, but also dynamic dive-in during acceleration and braking.