Broadening the temperature range in accelerated testing of electronic products is a typical measure to assure that the product of interest is sufficiently robust. At the same time, a too broad temperature range can lead to the shift in the modes and mechanisms of failure, i.e., result in failures that will not occur in actual operation conditions. Application of mechanical prestressing of the test specimen could be an effective means for narrowing the temperature range during accelerated testing and thereby achieving trustworthy and failure-mode-shift-free accelerated test information. Accordingly, simple engineering predictive models are developed for the evaluation of the magnitude and the distribution of thermal and mechanical stresses in a prestressed bow-free test specimen. A design, in which an electronic or a photonic package is bonded between two identical substrates, is considered. Such a design is often employed in some today's packaging systems, in which the “inner,” functional, component containing active and/or passive devices and interconnects is placed between two identical “outer” components (substrates). The addressed stresses include normal stresses acting in the component cross sections and the interfacial shearing and peeling stresses. Although the specimen as a whole remains bow-free, the peeling stresses might be nevertheless appreciable, since the outer components, if thin enough, deflect to a greater or lesser extent with respect to the inner component. The numerical example has indicated that the maxima of the interfacial thermal shearing and peeling stresses are indeed comparable and that these maxima are on the same order of magnitude as the normal thermal stresses acting in the components' cross sections. It is shown that since the thermal and the prestressing mechanical loads are of different physical nature, the stresses caused by these two load categories are distributed differently over the specimen's length. It is shown also that although it is possible and even advisable to apply mechanical prestressing for a lower temperature range, it is impossible to reproduce the same stress distribution as in the case of thermal loading. The obtained results enable one to shed light on the physics of the state of stress in prestressed bow-free test specimens in electronics and photonics engineering.

References

References
1.
Timoshenko
,
S.
,
1925
, “
Analysis of Bi-Metal Thermostats
,”
J. Opt. Soc. Am.
,
11
(
3
), pp.
233
255
.10.1364/JOSA.11.000233
2.
Aleck
,
B. J.
,
1949
, “
Thermal Stresses in a Rectangular Plate Clamped Along an Edge
,”
ASME J. Appl. Mech.
,
16
, pp.
118
122
.
3.
Boley
,
B. A.
, and
Weiner
,
J. H.
,
1974
,
Theory of Thermal Stresses
,
Quantum
,
New York
.
4.
Grimado
,
P. B.
,
1978
, “
Interlaminated Thermo-Elastic Stresses in Layered Beams
,”
J. Therm. Stresses
,
1
(
1
), pp.
75
86
.10.1080/01495737808926932
5.
Chang
,
F.-V.
,
1983
, “
Thermal Contact Stresses of Bi-Metal Strip Thermostat
,”
Appl. Math. Mech.
,
4
(
3
), pp.
347
360
.10.1007/BF01875666
6.
Kuo
,
A.
,
1989
, “
Thermal Stresses at the Edge of a Bimetallic Thermostat
,”
ASME J. Appl. Mech.
,
56
(
3
), pp.
585
589
.10.1115/1.3176131
7.
Eischen
,
J. W.
,
Chung
,
C.
, and
Kim
,
J. H.
,
1990
, “
Realistic Modeling of the Edge Effect Stresses in Bimaterial Elements
,”
ASME J. Electron. Packag.
,
112
(
1
), pp.
143
148
.10.1115/1.2904333
8.
Namson
,
S. S.
,
1996
,
Thermal Stress and Low Cycle Fatigue
,
McGraw-Hill
,
New York
.
9.
Carrera
,
E.
,
2000
, “
An Assessment of Mixed and Classical Theories for the Thermal Stress Analysis of Orthotropic Multilayered Plates
,”
J. Therm. Stresses
,
23
(
9
), pp.
797
831
.10.1080/014957300750040096
10.
Noda
,
N.
,
Hetnarski
,
R. B.
, and
Tanigawa
,
Y.
,
2004
,
Thermal Stress
,
2nd ed.
,
Taylor & Francis
,
London
.
11.
Ceniga
,
L.
,
2008
,
Analytical Models of Thermal Stresses in Composite Materials
,
Nova Science
,
New York
.
12.
Lanin
,
A.
, and
Fedik
,
I.
,
2008
,
Thermal Stress Resistance of Materials
,
Springer
,
New York
.
13.
Lang
,
G. A.
,
Fehder
,
B. J.
, and
Williams
,
W. D.
,
1970
, “
Thermal Fatigue in Silicon Power Devices
,”
IEEE Trans. Electron Devices
,
17
(
9
), pp.
787
793
.10.1109/T-ED.1970.17074
14.
Zeyfang
,
R.
,
1971
, “
Stresses and Strains in a Plate Bonded to a Substrate: Semiconductor Devices
,”
Solid-State Electron.
,
14
(
10
), pp.
1035
1039
.10.1016/0038-1101(71)90172-9
15.
Chen
,
W. T.
, and
Nelson
,
C. W.
,
1979
, “
Thermal Stresses in Bonded Joints
,”
IBM J. Res. Dev.
,
23
(
2
), pp.
179
188
.10.1147/rd.232.0179
16.
Chen
,
D.
,
Cheng
,
S.
, and
Geerhardt
,
T. D.
,
1982
, “
Thermal Stresses in Laminated Beams
,”
J. Therm. Stresses
,
5
(1), pp.
67
84
.10.1080/01495738208942136
17.
Suhir
,
E.
,
1986
, “
Stresses in Bi-Metal Thermostats
,”
ASME J. Appl. Mech.
,
53
(
3
), pp.
657
660
.10.1115/1.3171827
18.
Lau
,
J. H.
, ed.,
1993
,
Thermal Stress and Strain in Microelectronics Packaging
,
Van Nostrand Reinhold
,
New York
.
19.
Suhir
,
E.
,
1999
, “
Adhesively Bonded Assemblies With Identical Non-deformable Adherends: Predicted Thermal Stresses in the Adhesive Layer
,”
Compos. Interfaces
,
6
(
2
), pp.
135
154
.10.1163/156855499X00350
You do not currently have access to this content.