Process-dependence of properties in high thermal conductivity aluminum nitride substrates for electronic packaging.
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Authors
Cooper, John H.
Subjects
aluminum nitride
microelectronic packaging
liquid phase sintering
ceramic
yttria dopant
thermal conductivity
microelectronic packaging
liquid phase sintering
ceramic
yttria dopant
thermal conductivity
Advisors
Dutta, Indranath
Mitra, Shantanu
Date of Issue
1991-12
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
The development of secondary phases due to the presence of Y2O3 additions during
sintering of Aluminum Nitride was studied. Depending on the amount of Y2O3 added,
two non-equilibrium phases (cubic YAIO3 and orthorhombic AIYO3) were found to be
present at room temperature, in addition to equilibrium AI5Y3O12 and AI2Y4O9. Sintering
at increasing temperatures was found to alter the proportions of the above phases. This
appreciably affected physical properties and mechanical properties like density, stiffness,
strain to fracture, and failure morphology. These changes were rationalized on the basis
of the microstructural effects of sintering. TEM studies were also conducted to
investigate the evolution of bulk and surface defects in sintered AIN during processing.
In the low Y2O3 containing samples, heat treatment at 1850°C resulted in a 2 phase
mixture of Y-aluminate and 7-AI2O3 at the triple grain boundaries in AIN. Based on
these results, a mechanism for the sintering process is proposed.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
84 p.;28 cm.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.