The time- and temperature-dependent deformation behavior of two Sn-Ag base alloys, 96Sn-4Ag and Castin (96.2Sn-2.5Ag-0.8Cu-0.5Sb), used as solder interconnect materials was determined over strain rates ranging from 106s1 to 102s1 and temperatures ranging from −55°C–125°C. Uniaxial strain rate jump tests along with isothermal and thermomechanical cyclic tests were conducted. The constitutive behavior of each alloy was modeled with both a simple power law creep equation and the McDowell unified creep-plasticity model. Accumulated deformation under unconstrained thermal cycling was also measured to determine the relative dimensional stability due to internal constraints in the alloy itself. Overall, the Castin alloy appeared to be more stable and was more resistant to inelastic deformation.

1.
Lead-Free Solder Project, 1997, Final Report, Report 0401RE96, Project No. 170502-92031, Aug. 1997, National Center for Manufacturing Sciences, Ann Arbor, MI.
2.
Tribula
,
D.
,
Grivas
,
D.
,
Frear
,
D. R.
,
Morris
, Jr.,
J. W.
,
1989
, “
Observations on the Mechanisms of Fagitue in Eutectic Pb-Sn Solder Joints
,”
ASME J. Electron. Packag.
,
111
, pp.
83
89
.
3.
Artaki, I., Jackson, A. M., and Vianco, P. T., 1994, “Fine Pitch Surface Mount Assembly with Lead-Free, Low Residue Solder Paste,” Proc. Surface Mount Int. Conf. And Exposition, pp. 449–459.
4.
Vianco, P. T., Artaki, I., and Jones, A. M., 1994, “Reliability Studies of Surface Mount Boards Manufactured with Lead-Free Solders,” Proc. Surface Mount Int. Conf. And Exposition, pp. 437–448.
5.
Vaynman, S., Mavoori, H., and Fine, M. E., 1995, “Comparison of Isothermal Fatigue of Lead-Free Solders with Lead-Tin Solders,” Advances in Electronic Packaging, EEP-Vol. 10-2, ASME, pp. 657–661.
6.
Whitelaw
,
R. S.
,
Neu
,
R. W.
, and
Scott
,
D. T.
,
1999
, “
Deformation Behavior of Two Lead-Free Solders: Indalloy 227 and Castin Alloy
,”
ASME J. Electron. Packag.
,
121
, pp.
99
107
.
7.
Solomon
,
H. D.
,
1991
, “
Low Cycle Fatigue of Sn96 Solder with Reference to Eutectic Solder and a High Pb Solder
,”
ASME J. Electron. Packag.
,
113
, No.
2
, pp.
102
108
.
1.
Chada
,
S.
,
Herrmann
,
A.
,
Laub
,
W.
,
Fournelle
,
R.
,
Shangguan
,
D.
, and
Achari
,
A.
,
1997
, “
Microstructural Investigation of Sn-Ag and Sn-Pb-Ag Solder Joints
,”
Soldering & Surface Mount Technology
,
9
, No.
2
, pp.
9
13
;
2.
9
, No.
2
, p.
21
21
.
1.
Choi, S. L., Gibson, A. W., McDougall, J. L., Bieler, T. R., and Subramanian, K. N., 1997, “Mechanical Properties of Sn-Ag Composite Solder Joints Containing Copper-Based Intermetallics,” Design Reliability of Solders and Solder Interconnections, R. K. Mahidhara et al., eds., TMS, pp. 241–245.
2.
Yang
,
W.
,
Felton
,
L. E.
, and
Messler
, Jr.,
R. W.
,
1995
, “
The Effect of Soldering Process Variables on the Microstructure and Mechanical Properties of Eutectic Sn-Ag/Cu Solder Joints
,”
J. Electron. Mater.
,
24
, No.
10
, pp.
1465
1472
.
3.
Yang
,
W.
,
Messler
, Jr.,
R. W.
, and
Felton
,
L. E.
,
1994
, “
Microstructure Evolution of Eutectic Sn-Ag Solder Joints
,”
J. Electron. Mater.
,
23
, No.
8
, pp.
765
772
.
4.
Gibson, A. W., Choi, S. L., Subramanian, K. N., and Bieler, T. R., 1997, “Issues Regarding Microstructural Coarsening Due to Aging of Eutectic Tin-Silver Solder,” Design Reliability of Solders and Solder Interconnections, R. K. Mahidhara et al., eds., TMS, pp. 97–103.
5.
Scott, D. T., 1998, “Phenomenological Modeling of the Deformation Behavior of Solders,” M. S. thesis, Georgia Institute of Technology, Atlanta, GA.
6.
Mavoori
,
H.
,
Chin
,
J.
,
Vaynman
,
S.
,
Moran
,
B.
,
Keer
,
L.
, and
Fine
,
M.
,
1997
, “
Creep, Stress Relaxation, and Plastic Deformation in Sn-Ag and Sn-Zn Eutectic Solders
,”
J. Electron. Mater.
,
26
, No.
7
, pp.
783
790
.
7.
Takemoto, T., Ninomiya, R., Takahashi, M., and Matsunawa, A., 1997, “Mechanical Properties and Estimation of Thermal Fatigue Properties of Lead-Free Solders,” Advances in Electronic Packaging, EEP-Vol. 19-2, ASME, pp. 1623–1628.
8.
Raj, S. V., Iskovitz, I. S., and Freed, A. D., 1996, “Modeling the Role of Dislocation Substructure during Class M and Exponential Creep,” Unified Constitutive Laws of Plastic Deformation, A. S. Krausz and K. Krausz, eds., Academic Press, pp. 343–439.
9.
McDowell
,
D. L.
,
1992
, “
A Nonlinear Kinematic Hardening Theory for Cyclic Thermoplasticity and Thermoviscoplasticity
,”
Int. J. Plast.
,
8
, pp.
695
728
.
10.
McDowell, D. L., Miller, M. P., and Brooks, D. C., 1994, “A Unified Creep-Plasticity Theory for Solder Alloys,” Fatigue of Electronic Materials, ASTM STP 1153, S. A. Schroeder and M. R. Mitchell, eds., American Society for Testing and Materials, Philadelphia, pp. 42–59.
11.
Neu
,
R. W.
,
Scott
,
D. T.
, and
Woodmansee
,
M. W.
,
2000
, “
Measurement and Modeling of Back Stress at Intermediate to High Homologous Temperatures
,”
Int. J. Plast.
,
16
, pp.
283
301
.
12.
Fu
,
C.
,
McDowell
,
D. L.
, and
Ume
,
I. C.
,
1998
, “
Finite Element Procedure of a Cyclic Thermoviscoplasticity Model for Solder and Copper Interconnects
,”
ASME J. Electron. Packag.
,
120
, No.
1
, pp.
24
34
.
13.
Woodmansee, M. W. and Neu, R. W., 2000, “Response of 60Sn-40Pb Under Thermal and Mechanical Cycling,” Third Symposium on Thermo-mechanical Fatigue Behavior of Materials, ASTM STP 1371, H. Sehitoglu and H. J. Maier, eds., American Society for Testing and Materials, pp. 85–102.
14.
Boas
,
W.
and
Honeycombe
,
R. W. K.
,
1944
, “
The Plastic Deformation of Noncubic Metals by Heating and Cooling
,”
Proc. R. Soc. London, Ser. A
,
186
, pp.
57
71
.
You do not currently have access to this content.