Martin Willmann

H.-J. Kress; Frank Bantien; Jiri Dr Ing Dr Marek; Martin Willmann

Abstract A silicon pressure sensor designed for automotive applications with on-chip signal conditioning is presented. The micromechanical processing steps are added to a standard 3 μm CMOS process. The membrane is etched in (100)-oriented Si by anisotropic etching with an electrochemical etch stop. Thickness control with tolerances of less than 0.5 μm is readily achieved. A complete CMOS evaluation circuit is integrated on the same device. The signal of the piezoresistive Wheatstone bridge is processed by an instrumentation amplifier with temperature-dependent amplification for on-chip compensation of the sensitivity variation with temperature. Moreover, the sensitivity variation itself, the offset and the offset variation with temperature are compensated. On-chip trimming is provided for the adjustment of these terms in the full automotive temperature range from −40 °C to + 125 °C.

C. Döring; Thomas Dr. Dipl.-Phys. Grauer; Jiri Marek; M.S. Mettner; H.-P. Trah; Martin Willmann

The design, fabrication, and performance of bimorph cantilever structures for direction control of laminar jet flow are reported. The fabrication process comprises standard IC technologies and additional silicon micromachining techniques. The design parameters for the structures are obtained using analytical approximations and numerical simulations. Forced convection as the decisive cooling mechanism proves to be very effective, resulting in an excellent dynamic response of the thermoelectrically activated structures. Experimental testing confirmed the predicted stationary and transient behavior of 1-mm-long and 1-mm-wide actuators, which are able to control hydraulic power at pressure levels of up to 4 bar, flow rates of up to 150 ml/min, and time constants of about 1 ms.<<ETX>>

H.-J. Kress; Frank Bantien; Jiri Dr Ing Dr Marek; Martin Willmann

A silicon pressure sensor with an integrated signal conditioning circuit has been developed for automotive applications. The sensor is fabricated with a standard 3μm CMOS process. The membrane is formed by anisotropic etching in (100)-oriented silicon using an electrochemical etch stop. A complete signal conditioning circuit is added to amplify the Bridge output signal. Furthermore, the sensor offset, the sensitivity, and the temperature effects on offset and sensitivity values are adjusted individually. Compensation is done for a temperature range from −40 to +125°C. On-chip trimming is provided for the adjustment of the correction values.

Christian Doering; Thomas Dipl Phys Dr Grauer; Michael Mettner; Armin Schuelke; Jiri Marek; Hans-Peter Trah; Joerg Muchow; Martin Willmann

Rolf Becker; Klaus Jaeckel; Jiri Marek; Frank Bantien; Helmut Baumann; Kurt Weiblen; Martin Willmann

Michael Offenberg; Martin Willmann

Gerhard Benz; Jiri Marek; Martin Willmann; Frank Bantien; Horst Muenzel; Franz Laermer; Michael Offenberg; Andrea Schilp

Nils Kummer; Jiri Marek; Martin Willmann; Guenther Dipl Ing Findler

Jiri Marek; Micheal Dr. Dipl.-Ing. Mettner; Martin Willmann; Jörg Dipl.-Ing. Muchow; Armin Schuelke; Thomas Dr. Dipl.-Phys. Grauer; Hans-Peter Trah; Christian Doering

Jiri Marek; Helmut Baumann; Guenther Dipl Ing Findler; Michael Offenberg; Martin Willmann