PHOTOLITHOGRAPHIC STRUCTURING OF THIN-FILM SENSORS FOR EHL MEASUREMENTS

The transmission of force in the lubricating films of disk test stands, cam-follower-systems or between gear tooth flanks obeys the laws of the Elastohydrodynamic Lubrication (EHL). It is state of the art to measure pressure, temperature and film profiles in EHL-gaps with thin film sensors which move through the contact. With respect to the dimensions of an EHL-contact, scanning the profiles in detail requires very small sensors, which are usually manufactured in vacuum using small apertures. As an alternative a photolithographic process is presented. This process enables sensor structures to be produced directly on the component part down to the range of micrometers. It is possible to provide the surface, usually curved, with several sensors in one step. Furthermore, their contours may be designed at pleasure. The process takes place outside the vacuum and is, therefore, very flexible.