University of Minnesota
Aerospace Engineering and Mechanics
Spring 2000 Seminar Series



Failure Prevention by Compressive Surface Stresses


Prof. Robert Cook

Department of Chemical Engineering and Materials Science, University of Minnesota


Abstract

Controlled-flaw indentation techniques are described and used to characterize the equilibrium and non-equilibrium fracture properties of cordierite glass-ceramic—a material used in microelectronic substrates. Attention is focused on an indentation fracture-mechanics analysis developed for the behavior of cracks in multilayer structures and used to describe the effects of a compressive surface stress. In the test case examined, significant enhancements in mechanical properties were achieved via a mechanism that prevented mechanical failure but which did not degrade substrate electrical performance or manufacturability; surface compression was introduced by a small compositional modification of the multilayer substrate's outer layers leading to a thermal expansion mismatch with the inner layers.


Friday, January 28, 2000
209 Akerman Hall
2:30-3:30 p.m.


Refreshments served after the seminar in 227 Akerman Hall.
Disability accomodations provided upon request.
Contact Kristal Belisle, Principal Secretary, 625-8000.