The Mechanisms of Fatigue and Fracture of Metal/Ceramic Interfaces

Introduction

     Multi-layered and composite systems, which often contain metal/ceramic interfaces, are widely used in industry, both in microelectronic packaging and structural materials.  In order to make long-term reliable multi-layered electronic devices and reliable structural composites, the fatigue and fracture behavior of material interfaces needs to be well understood.  Thus, the need to understand what governs the mechanical properties of the interfaces between these dissimilar materials becomes important as the mechanical properties of these interfaces ultimately control the reliability of the device.

Background

     One model metal/ceramic interface system which has been studied here at Berkeley, Al/Al2O3, is also of some practical interest as thin layers of pure aluminum are commonly used in the microelectronics industry as conductors.  Previous investigations (Int. J. Fract., 66, 1994, pp. 227 and  Acta Mat. 44 1996, pp. 4713) into the fracture and fatigue behavior of these types of interfaces for 99.999% pure aluminum layers, 100 - 500 mm thick, sandwiched between 99.5% pure alumina have shown:

Continuing Research

     Previous results have indicated that plastic dissipation and constraint in the metal layer may be important and effect the fracture and fatigue behavior in a variety of ways.  Research continues, on the effect of constraint as metal layer thickness is reduced, in the following areas: Furthermore, it is the goal of this research to investigate the fracture and fatigue behavior Al/Al2O3 interfaces in sandwich specimens where the thickness of the metal layers are in the range of 1mm - 100mm to further understand the role of constraint in the metal layer.
 

Current Researchers:

                                J. J. Kruzic
                                R. M. Cannon
                                R. O. Ritchie

Recent Publications:

Publications of the Ritchie Group on the Fatigue and Fracture of Bimaterial Interfaces


LBNL, MSD * Ritchie Group * Dept. of MSME, UC Berkeley