scholarly journals Microstructure and Damage Evolution During Thermal Cycling of Sn-Ag-Cu Solders Containing Antimony

2020 ◽  
Author(s):  
S. A. Belyakov ◽  
R. J. Coyle ◽  
B. Arfaei ◽  
J. W. Xian ◽  
C. M. Gourlay
Keyword(s):  
Thermal Cycling ◽  
Damage Evolution ◽  
Eutectic Reaction ◽  
Cycling Performance ◽  
Orientation Relationships ◽  
Lattice Match ◽  
Bga Packages ◽  
Good Lattice ◽  
Accelerated Thermal Cycling ◽  
Strengthening Particles

Abstract Antimony is attracting interest as an addition to Pb-free solders to improve thermal cycling performance in harsher conditions. Here, we investigate microstructure evolution and failure in harsh accelerated thermal cycling (ATC) of a Sn-3.8Ag-0.9Cu solder with 5.5 wt.% antimony as the major addition in two ball grid array (BGA) packages. SbSn particles are shown to precipitate on both Cu6Sn5 and as cuboids in β-Sn, with reproducible orientation relationships and a good lattice match. Similar to Sn-Ag-Cu solders, the microstructure and damage evolution were generally localised in the β-Sn near the component side where localised β-Sn misorientations and subgrains, accelerated SbSn and Ag3Sn particle coarsening, and β-Sn recrystallisation occurred. Cracks grew along the network of recrystallised grain boundaries to failure. The improved ATC performance is mostly attributed to SbSn solid-state precipitation within β-Sn dendrites, which supplements the Ag3Sn that formed in a eutectic reaction between β-Sn dendrites, providing populations of strengthening particles in both the dendritic and eutectic β-Sn.

Thermo-Mechanical Fatigue Life Estimation of Organic BGA Packages Using Laser Moire Interferometry

2006 ◽  
Author(s):  
Krishna Tunga ◽  
Suresh K. Sitaraman
Keyword(s):  
Fatigue Life ◽  
Thermal Cycling ◽  
Deformation Behavior ◽  
Life Estimation ◽  
Mechanical Fatigue ◽  
Joint Reliability ◽  
Bga Packages ◽  
Fatigue Life Estimation ◽  
Bga Package ◽  
Accelerated Thermal Cycling

Accelerated Thermal Cycling (ATC) is traditionally used for assessing solder joint reliability. ATC typically takes as long as three to four months to complete. This paper proposes a new method to determine the fatigue life of solder joints using laser moire´ technique. The developed method takes about a week to complete and gives us the detailed deformation behavior of each solder ball in the package at various temperatures. The developed method has been demonstrated for a high I/O organic BGA package. To illustrate the efficacy of the method, the results have been validated using experimental thermal cycling data.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

A Highly Accelerated Thermal Cycling (HATC) Test for Solder Reliability Assessment in BGA Packages

2007 ◽  
Author(s):  
X. Long ◽  
I. Dutta ◽  
R. Guduru ◽  
R. Prasanna ◽  
M. Pacheco
Keyword(s):  
Thermal Cycling ◽  
Solder Joints ◽  
Low Cycle Fatigue ◽  
Inelastic Strain ◽  
Fatigue Reliability ◽  
Element Analysis ◽  
Mechanical Cycling ◽  
Experimental Apparatus ◽  
Dependent Strain ◽  
Accelerated Thermal Cycling

A thermo-mechanical loading system, which can superimpose a temperature and location dependent strain on solder joints, is proposed in order to conduct highly accelerated thermal-mechanical cycling (HATC) tests to assess thermal fatigue reliability of Ball Grid Array (BGA) solder joints in microelectronics packages. The application of this temperature and position dependent strain produces generally similar loading modes (shear and tension) encountered by BGA solder joints during service, but substantially enhances the inelastic strain accumulated during thermal cycling over the same temperature range as conventional ATC (accelerated thermal cycling) tests, thereby leading to a substantial acceleration of low-cycle fatigue damage. Finite element analysis was conducted to aid the design of experimental apparatus and to predict the fatigue life of solder joints in HATC testing. Detailed analysis of the loading locations required to produce failure at the appropriate joint (next to the die-edge ball) under the appropriate tension/shear stress partition are presented. The simulations showed that the proposed HATC test constitutes a valid methodology for further accelerating conventional ATC tests. An experimental apparatus, capable of applying the requisite loads to a BGA package was constructed, and experiments were conducted under both HATC and ATC conditions. It is shown that HATC proffers much reduced cycling times compared to ATC.

Reliability analysis of low-Ag BGA solder joints using four failure criteria

2012 ◽  
Vol 2012 (1) ◽  
pp. 000066-000072
Author(s):  
Erin Kimura ◽  
Jianbiao Pan
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Failure Criterion ◽  
Control Charts ◽  
Failure Criteria ◽  
Life Estimation ◽  
Resistance Increase ◽  
Estimate Reliability ◽  
Accelerated Thermal Cycling ◽  
Selection Of

The appropriate selection of failure criterion for solder joint studies is necessary to correctly estimate reliability life. The objective of this study is to compare the effect of different failure criteria on the reliability life estimation. The four failure criteria in this study are a 20% resistance increase defined in the IPC-9701A standard, a resistance beyond 500Ω, an infinite resistance (hard open), and a failure criterion based on X̄ and R control charts. Accelerated thermal cycling conditions of a low-silver BGA study included 0°C to 100 °C with ten minute dwell times and −40°C to 125°C with ten minute dwell times. The results show that the life estimation based on X̄ and R failure criterion is very similar to the life estimation when a 20% resistance increase defined in the IPC-9701A failure criterion is used. The results also show that the reliability life would be overestimated if the failure criterion of a resistance threshold of 500Ω or an infinite resistance (hard open) is used.

Impact of isothermal aging on fine pitch BGA packages with Sn-Ag-Cu solder interconnects

2010 ◽  
Vol 2010 (1) ◽  
pp. 000298-000305
Author(s):  
Tae-Kyu Lee ◽  
Weidong Xie ◽  
Thomas R. Bieler ◽  
Kuo-Chuan Liu ◽  
Jie Xue
Keyword(s):  
Thermal Cycling ◽  
Microstructure Evolution ◽  
Isothermal Aging ◽  
Substrate Surface ◽  
Solder Interconnects ◽  
Surface Finishes ◽  
Bga Packages ◽  
Fine Pitch ◽  
Solder Balls

The interaction between isothermal aging and long-term reliability of fine pitch ball grid array (BGA) packages with Sn-3.0Ag-0.5Cu (wt%) solder ball interconnects are investigated. In this study, 0.4mm fine pitch packages with 0.3mm diameter Sn-Ag-Cu solder balls are used. Two different die sizes and two different package substrate surface finishes are selected to compare the internal strain impact and alloy effect, especially the Ni effect during thermal cycling. To see the thermal impact on the thermal performance and long-term reliability, the samples are isothermally aged and thermal cycled from 0 to 100°C with a 10minute dwell time. Based on weibull plots for each aging condition, the lifetime of the package reduced approximately 44% with 150°C aging precondition. The microstructure evolution is observed during thermal aging and thermal cycling with different phase microstructure transformations between electrolytic Ni/Au and OSP surface finishes, focusing on the microstructure evolution near the package side interface. Different mechanisms after aging at various conditions are observed, and their impacts on the fatigue life of solder joints are discussed.

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