Investigating the Reliability of SnAgCu Solder Alloys at Elevated Temperatures in Microelectronic Applications

Aging affects both microstructure and behavior [1, 2]. Microstructural changes are driven by dislocation motion and diffusion processes. Together they affect the flow behavior in solder alloys. We address four aspects of solder microstructure and behavior as affected by aging (a) EDS studies on Ag dispersion in Sn matrix (b) a procedure for modeling intermetallic particle growth (c) a model for estimating effective viscosity of solder alloy (d) both primary and secondary creep models to predict aging effects on behavior. Solder samples were aged for different aging times (15, 30, 60, 90 days aging) and at different aging temperatures (25 C, 75 C, 125 C) prior to running creep tests. Another set of solder samples were similarly aged to characterize the microstructure. The creep data for the experiments are from a series of sixty four experiments performed using a micromechanical tester that is specially fitted with a sensitive capacitance gauge (with a resolution of 0.1 microns) to accurately measure viscoplastic responses of solder to applied loads.

Download Full-text

DSC investigation of the undercooling of SnAgCu solder alloys

2016 39th International Spring Seminar on Electronics Technology (ISSE) ◽

10.1109/isse.2016.7563160 ◽

2016 ◽

Author(s):

Maik Mueller ◽

Alexander Turke ◽

Iuliana Panchenko

Keyword(s):

Solder Alloys ◽

Snagcu Solder

Download Full-text

Investigating the Fine Microstructure of Mn-doped SnAgCu Solder Alloys by Selective Electrochemical Etching

2018 7th Electronic System-Integration Technology Conference (ESTC) ◽

10.1109/estc.2018.8546411 ◽

2018 ◽

Author(s):

Oliver Krammer ◽

Tamas Hurtony

Keyword(s):

Electrochemical Etching ◽

Solder Alloys ◽

Snagcu Solder ◽

Fine Microstructure ◽

Mn Doped

Download Full-text

Low-temperature creep of SnPb and SnAgCu solder alloys and reliability prediction in electronic packaging modules

Scripta Materialia ◽

10.1016/j.scriptamat.2012.12.017 ◽

2013 ◽

Vol 68 (8) ◽

pp. 607-610 ◽

Cited By ~ 34

Author(s):

Yuming Zhang ◽

Honglai Zhu ◽

Masami Fujiwara ◽

Jinquan Xu ◽

Ming Dao

Keyword(s):

Low Temperature ◽

Electronic Packaging ◽

Reliability Prediction ◽

Solder Alloys ◽

Snagcu Solder ◽

Temperature Creep ◽

Low Temperature Creep

Download Full-text

Constitutive Behavior of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu Alloys at Creep and Low Strain Rate Regimes

Volume 5: Electronics and Photonics ◽

10.1115/imece2007-44151 ◽

2007 ◽

Cited By ~ 2

Author(s):

D. Bhate ◽

D. Chan ◽

G. Subbarayan ◽

T. C. Chiu ◽

V. Gupta ◽

...

Keyword(s):

Test Data ◽

Constitutive Models ◽

Bulk Sample ◽

Lead Free ◽

Creep Model ◽

Model Parameters ◽

Solder Alloys ◽

Snagcu Solder ◽

Reported Data ◽

Lead Free Solders

Constitutive models for SnAgCu solder alloys are of great interest at the present. Commonly, constitutive models that have been successfully used in the past for Sn-Pb solders are used to describe the behavior of SnAgCu solder alloys. Two issues in the modeling of lead-free solders demand careful attention: (i) Lead-free solders show significantly different creep strain evolution with time, stress and temperature, and the assumption of evolution to steady state creep nearly instantaneously may not be valid in SnAgCu alloys and (ii) Models derived from bulk sample test data may not be reliable when predicting deformation behavior at the solder interconnection level for lead-free solders due to the differences in the inherent microstructures at these different scales. In addition, the building of valid constitutive models from test data derived from tests on solder joints must deconvolute the effects of joint geometry and its influence on stress heterogeneity. Such issues have often received insufficient attention in prior constitutive modeling efforts. In this study all of the above issues are addressed in developing constitutive models of Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys, which represent the extremes of Ag composition that have been mooted at the present time. The results of monotonic testing are reported for strain rates ranging from 4.02E-6 to 2.40E-3 s−1. The creep behavior at stress levels ranging from 7.8 to 52 MPa are also described. Both types of tests were performed at temperatures of 25°C, 75°C and 125°C. The popular Anand model and the classical time-hardening creep model are fit to the data and the experimentally obtained model parameters are reported. The test data are compared against other reported data in the literature and conclusions are drawn on the plausible sources of error in the data reported in the prior literature.

Download Full-text