The determination of material parameters of
microcomponents using digital holography
S.Seebacher, W.Osten*, T.Baumbach, W.J .uptner
BIAS, Bremer Institut f . ur Angewandte Strahltechnik, Klagenfurter Str. 2, D-28359 Bremen, Germany
Abstract
Progresses in microsystem technology promise a lot of new applications in industry and
research.However, the increased complexity of the microsystems demand sensitive and robust
measurement techniques.Fullfield and non invasive methods are desirable to get access to
spatially resolved material properties and parameters.
This contribution describes a simple and fast interferometric method for the analysis of
shape and deformation of small objects by optical means.These quantities together with a well
defined loading of the components can be the starting point for the determination of material
parameters like Poisson-ratio, Young’s modulus or the thermal expansion coefficient.
A new adaptive, iterative algorithm is developed and applied to the measured results that
allows the numerical evaluation of the phase data to get absolute shape and deformation
information in Cartesian coordinates.Surfaces with holes, gaps and steps can be registered
without any ambiguities.Digital holography as the underlying holographic recording
mechanism is extremely suitable for small objects and lead to simple and compact setups in
which the objects’ shape as well as their deformation behavior can be recorded.Experiments
using silicon microbeams and an object from fine mechanics are described to show the great
potential of these fast and robust measurement techniques with respect to the determination of
material parameters. r 2001 Elsevier Science Ltd.All rights reserved.