The effects of specimen geometry size on the behavior of 63Sn-37Pb solder are investigated both experimentally in the laboratory and analytically with finite-element simulations. The simulations are achieved by developing a constitutive model for solder which couples viscoplasticity with a unified damage theory. The unified damage theory is characterized by a damage surface in strain space which separates fatigue damage from inelastic damage. The damage evolution equations are derived within the framework of irreversible thermodynamics. A series of uniaxial tension, tensile creep, and strain-controlled fatigue experiments are performed to obtain material parameters for the solder damage model. The solder damage model is then implemented into a finite element code and used to simulate a uniaxial tension test on a miniature specimen and on a standard ASTM specimen (ASTM Standards, 1999, “Tension Testing of Metallic Materials,” ASTM E8-78). Predictions from these simulations are then compared with each other and with experimental results in order to examine microstructure size effects.

1.
Basaran
,
C.
, and
Yan
,
C. Y.
,
1998
, “
A Thermodynamic Framework for Damage Mechanics of Solder Joints
,”
ASME J. Electron. Packag.
,
120
, pp.
379
384
.
2.
Wei, Y., Chow, C. L., Fang, H. E., and Neilsen, M. K., 2000, “Constitutive Modeling of Viscoplastic Damage in Solder Material,” IUTAM Symposium on Creep in Structures, Kluwer Academic Publishers, pp. 131–140.
3.
Wei
,
Y.
,
Chow
,
C. L.
,
Fang
,
H. E.
, and
Neilsen
,
M. K.
,
2001
, “
Characteristics of Creep Damage for 60Sn-40Pb Solder Material
,”
ASME J. Electron. Packag.
,
123
, pp.
278
283
.
4.
Lemaitre, J., and Chaboche, J. L., 1990, Mechanics of Solid Materials, Cambridge University Press.
5.
Kachanov
,
L. M.
,
1958
, “
On Creep Rupture Time
,”
Izv. Acad. Nauk SSSR, Otd. Techn. Nauk
,
8
, pp.
26
31
.
6.
Chow
,
C. L.
, and
Wang
,
J.
,
1987
, “
An Anisotropic Theory of Continuum Damage Mechanics for Ductile Fracture
,”
Eng. Fract. Mech.
,
27
, pp.
547
558
.
7.
Chow
,
C. L.
, and
Wei
,
Y.
,
1991
, “
A Model of Continuum Damage Mechanics for Fatigue Fracture
,”
Int. J. Fract.
,
50
, pp.
301
316
.
8.
Chow
,
C. L.
, and
Wei
,
Y.
,
1991
, “
A Damage Mechanics Model of Fatigue Crack Initiation in Notched Plates
,”
Theor. Appl. Fract. Mech.
,
16
, pp.
123
133
.
9.
Chow, C. L., and Wei, Y., 1996, “A Fatigue Damage Model for Crack Propagation,” Advances in Fatigue Lifetime Predictive Techniques, ASTM STP 1292, pp. 86–99.
10.
Wei
,
Y.
,
Chow
,
C. L.
, and
Liu
,
C. T.
,
2000
, “
Damage Analysis for Mixed Mode Crack Initiation
,”
Computer Modeling in Engineering & Sciences
,
1
, pp.
115
121
.
11.
Wei, Y., Chow, C. L., Neilsen, M. K., and Fang, H. E., 2000, “Damage Mechanics Based Fatigue Life Prediction for 63Sn-37Pb Solder Material,” ASME International Mechanical Engineering Congress & Exposition, EEP-Vol. 28, pp. 161–165.
12.
Frear, D. R., Burchett, S. N., Neilsen, M. K., and Stephens, J. J., 1997, “Microstructurally Based Finite Element Simulation of Solder Joint Behavior,” Soldering & Surface Mount Technology Vol. 2, pp. 39–42.
13.
Vianco
,
P. T.
,
Burchett
,
S. N.
,
Neilsen
,
M. K.
,
Rejent
,
J. A.
, and
Frear
,
D. R.
,
1999
, “
Coarsening of the Sn-Pb Solder Microstructure in Constitutive Model Based Prediction of Solder Joint Thermal Mechanical Fatigue
,”
J. Electron. Mater.
,
28, 11
, pp.
1290
1298
.
14.
Fu
,
C.
,
McDowell
,
D. L.
, and
Ume
,
I. C.
,
1998
, “
A Finite Element Procedure of a Cyclic Thermoviscoplasticity Model for Solder and Copper Interconnects
,”
ASME J. Electron. Packag.
,
120
, pp.
24
34
.
15.
Lim, T. J., and Lu, W., 2000, “Length Scale and Aging Effect on the Mechanical Properties of a 63Sn-37Pb Solder Alloy,” ASME International Mechanical Engineering Congress & Exposition, EEP-Vol. 28, pp. 203–206.
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