Today MEMS inertial sensors have already entered a broad market area and have mastered the step into high volume mass production, as seen on 3-axis accelerometers. The competitive product innovation cycle however gives constant pressure on the development of multi-axis and multi-type sensor systems to finally conclude in a full inertial measurement unit (IMU). Up to now the combination of accelerometer and gyrometer on one chip was limited by the incompatibility of the different operational pressure requirements. In this paper we introduce a new technology approach enabling the allocation of different cavity pressures on wafer level. This new concept is being industrialized with the new combi sensor SD755, which contains in a first step one accelerometer and one angular rate sensor on the same silicon chip

The fast growth of MEMS technologies for the production of inertial sensors in the last decade makes the characterization at wafer-level very important. In this paper is presented a test setup for measuring electrical and mechanical parameters of capacitive MEMS inertial sensors. The test setup is used in the production for automotive and consumer applications. It is fully electrical (i.e. none of the stimuli to the sensors is mechanical). The core of the test setup is a test algorithm. The design of the test algorithm was aimed at a fast, reliable and repeatable wafer-sort test. With the test setup described in this paper, it is possible to measure electrical and mechanical parameters of inertial sensors with up-to-6 dimensions

Small size, low power consumption and the capability to produce sharp images without need of an objective make MEMS scanning laser based pico-projectors an attractive solution for embedded cell-phone projection displays. To fulfil the high image resolution demands the MEMS scanning mirror has to show large scan angles, a large mirror aperture size and a high scan frequency. An additional important requirement in pico-projector applications is to minimize power consumption of the MEMS scanner to enable a long video projection time. Typically high losses in power are caused by gas damping. For that reason Fraunhofer ISIT has established a fabrication process for 2D-MEMS mirrors that includes vacuum encapsulation on 8-inch wafers. Quality factors as high as 145,000 require dedicated closed loop phase control electronics to enable stable image projection even at rapidly changing laser intensities. A capacitive feedback signal is the basis for controlling the 2D MEMS oscilla tion and for synchronising the laser sources. This paper reports on fabrication of two-axis wafer level vacuum packaged scanning micromirrors and its use in a compact laser projection display. The paper presents different approaches of overcoming the well-known reflex problem of packaged MEMS scanning mirrors

MEMS based laser projection is of high interest for automotive head-up displays and dashboard displays, as well as for an increasing number of personal mobile projection applications. These applications require scanning mirrors that offer high scan frequencies and wide scan angles while showing low power consumption. This paper presents a novel low-power high-Q scanning mirror that is vacuum encapsulated on wafer level and thereby exhibits Q-factors exceeding 145,000. A new glass forming process enables fabrication of glass wafers with inclined 3D-shaped windows needed to spatially separate the direct reflex from the projected image

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