SPIE 95 talk

Inductive Proximity Sensor using a Two-Coil Planar Transformer

Department of Electrical and Computer Engineering

Microelectronics Research Center

The University of Texas at Austin

Vikas Gupta* and Dean P. Neikirk

*current address: Texas Instruments

http://weewave.mer.utexas.edu/

This work was sponsored by the Advanced Research Projects Agency (ARPA) Embedded Microsystems Program under contract # DABT63-92-C-0027 AMD P00002- DOD-ARPA.

Inductive Proximity Sensor using a Two-Coil Planar Transformer

Motivation: gap measurement in micromachined smart bearings

Remote sensing of gap between surfaces

Conventional eddy current sensors

Miniaturized planar proximity sensor

Dual

Mutual inductance effects

Inductance calculations

Dual coil inductive sensor measurement

Scaling behavior for two coil sensor

Fabrication issues for micromachined proximity sensor

Photoresist coating

Photoresist profiles

Coil

Micromachined inductive proximity sensors