Integrated Microsystems

QUESTION Which components are combined in an integrated microsystem at ELMOS?

Keck When we use this term we mean products which contain more than a single integrated circuit, which is either provided in a standard package or as a bare die. These are primarily sensoric products. They typically contain a micro-mechanical sensor element and an IC for signal processing. Such sensor elements measure pressure, acceleration or rotation rates but also ambient brightness and temperature. The sensor element and IC can also be integrated on the same chip, which is what we call co-integration. Other microsystems in the ELMOS portfolio contain several integrated circuits – so called multi-chip modules – or integrate active or passive components.

Optical sensors are used in our HALIOS® product family or in rain-tunnel-light-sensors. Having our subsidiary, Silicon Microstructures in Milpitas, USA, and ELMOS Advanced Packaging in Nijmegen, Netherlands, we are able to offer these microsystems in a one-stop shop.

QUESTION What special features do these components have?

Keck Components, such as our co-integrated pressure sensor, have been designed to have extremely high calibration precision throughout the wide automotive temperature range of –40 to +125°C. Other pressure sensors are characterized by their extreme miniaturization made possible by state-of-the-art production technology. Concerning ASICs, the interaction of the analogue performance and the digital signal processing determine the system qualities; here we make use of our long-standing expertise in the mixed-signal circuitry development. The integral component is ultimately the package. Its mechanical qualities combined with the sensor determine the final system performance and are decisive for the application range.

QUESTION What technological advantages are created by this synergy?

Keck Our customers value the system competence in our one-stop-shop model, in one development team. As development is carried out from the start in comprehensive project teams including production experts, the system concepts are coordinated with regard to technical qualities and manufacturability. This vertical integration within the ELMOS group permits a continuous quality management - from product definition through to production. In addition, production continuity means that we can achieve exigent traceability concepts which are particularly relevant for safety-critical components.

QUESTION Which characteristics must one pay particular attention to while integrating the individual elements?

Keck A microsystem is more than just the sum of its individual components. Our comprehensive development ensures that the critical aspects such as interaction between package and sensor as well as the test and calibration concept for the complete system are taken into account at the early stages of the definition phase.

QUESTION Why are integrated microsystems suitable for car applications?

Keck Microsystems, particularly sensors, are mostly applied “on the spot”, i.e. in the peripherals. There the space for installation is scarce and there are adverse surroundings conditions regarding physical, chemical and electrical factors. In such surroundings, an integrated solution can take full advantage of its small dimensions and short signal paths with optimal protection provided by its plastic packaging. The current trend for digitalizing and networking bus systems is a further essential factor ensuring the success of microsystems in the automobile. The demand for digital communication makes a local mixed-signal IC practically indispensable. A good example is a side airbag pressure sensor which provides all essential analogue and digital signal processing and diagnostic functions in a microsystem directly and communicates with the airbag controller merely via a digital current modulated interface. Another example is our sensor module for tire pressure control which processes the analogue pressure and acceleration data internally, the information interchange with the outside world is carried out digitally only.

QUESTION What progress do you expect to see within the next years with regard to the integrated microsystems?

Keck Basically, we are observing evolutionary steps. Our challenge is to industrialize these technologies (which up to now have been implemented in small quantities), in a field where there are extremely high quality and ambient requirements and, finally, strong cost pressure. In addition, there is a trend for two chip solutions, especially for applications with complex digital parts or powerful microcontroller cores. Several such products are already being developed at ELMOS. A standardized package, particularly for the sensor, would be desirable, however will remain a dream due to the lack of potent drivers. However, the trend to increase miniaturization, in particular with regard to the package, remains.