X-ray diffraction imaging of fully packaged n–p–n
transistors under accelerated ageing conditions
Tanner, Brian KORCID: 0000-0002-1474-177X, Danilewsky, Andreas and McNally, Patrick J.ORCID: 0000-0003-2798-5121
(2022)
X-ray diffraction imaging of fully packaged n–p–n
transistors under accelerated ageing conditions.
Journal of Applied Crystallography, 55
.
pp. 1139-1146.
ISSN 0021-8898
X-ray diffraction imaging was used to monitor the local strains that developed
around individual n–p–n bipolar transistors within fully encapsulated packages
under conditions of extremely high forward bias to simulate accelerated ageing.
Die warpage associated with the packaging was observed to relax systematically
as the polymer became viscous due to the temperature rise associated with the
dissipation of heat in the transistor. The direct image size and intensity from the
individual transistors were interpreted in terms of a model in which local
thermal expansion is treated as a cylindrical inclusion of distorted material,
contrast arising principally from lattice tilt. The extension of the thermal strain
image along the emitter with increasing power dissipation was ascribed to the
effect of current crowding in the emitter region. Weaker large-area contrast
associated with the base–collector region was interpreted as arising from the
smaller change in effective misorientation at the high X-ray energy of thermal
lattice dilation in the base region.
Project CALIPSOplus (grant agreement No. 730872) from the EU Framework Programme for Research and Innovation HORIZON 202, Science Foundation Ireland (SFI) (grant No. 16/RC/3872) and is co-funded under the European Regional Development Fund
ID Code:
28201
Deposited On:
27 Mar 2023 14:43 by Patrick Mcnally. Last Modified 27 Mar 2023 14:51