Interfacial reactions and joint strength of Sn–37Pb and Sn–3.5Ag solders with immersion Ag-plated Cu substrate during aging at 150 °C

2006 ◽  
Vol 21 (12) ◽  
pp. 3196-3204 ◽  
Author(s):  
Jeong-Won Yoon ◽  
Jun Hyung Lim ◽  
Hoo-Jeong Lee ◽  
Jinho Joo ◽  
Seung-Boo Jung ◽  
...  
Keyword(s):  
Solder Joint ◽  
Eutectic Reaction ◽  
Bulk Solder ◽  
Interfacial Reactions ◽  
Test Results ◽  
Mechanical Reliability ◽  
Viable Option ◽  
Reaction Behavior ◽  
Cu Substrate ◽  
Joint Reliability

Joint reliability of immersion Ag with two different solders, Sn–37Pb and Sn–3.5Ag, were evaluated. We first compared the interfacial reactions of the two solder joints and also successfully revealed a connection between the interfacial reaction behavior and mechanical reliability. The Sn–Pb solder produced a Pb-rich phase along the interface between the solder and the Cu substrate during aging. In contrast, the Sn–Ag solder exhibits an off-eutectic reaction to produce the eutectic phase and Ag3Sn precipitate. The shear test results show that the Sn–Pb solder joint fractured along the interface showing brittle failure indications possibly due to the brittle Pb-rich layer. In contrast, the failure of Sn–Ag solder joint was only through the bulk solder, providing evidence that the interface is mechanically reliable. The results from this study confirm that the immersion Ag/Sn–Ag solder joint is mechanically robust, and thus the combination is a viable option for a Pb-free package system.

Study of interfacial reactions in Sn–3.5Ag–3.0Bi and Sn–8.0Zn–3.0Bi sandwich structure solder joint with Ni(P)/Cu metallization on Cu substrate

2007 ◽  
Vol 437 (1-2) ◽  
pp. 169-179 ◽  
Author(s):  
Peng Sun ◽  
Cristina Andersson ◽  
Xicheng Wei ◽  
Zhaonian Cheng ◽  
Dongkai Shangguan ◽  
...  
Keyword(s):  
Solder Joint ◽  
Sandwich Structure ◽  
Interfacial Reactions ◽  
Cu Substrate ◽  
Cu Metallization

Inverse Derivation of Constants for the Constitutive Equation and Fatigue Model of Pb-Free Solder Joints Based on Experiment Results, Finite Element Simulation and Virtual Optimization Methodology

2012 ◽  
Author(s):  
Weidong Xie ◽  
Mudasir Ahmad
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Constitutive Equation ◽  
Solder Joint ◽  
Test Results ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
Fatigue Model ◽  
End Use ◽  
Free Solder

Solder joint reliability of Pb-free ball grid array (BGA) components, one of the most commonly used microelectronic devices, is one of the major concerns in product development and qualification. Accelerated Thermal Cycling (ATC) testing, though very time consuming and costly, remains the most prevalent means to evaluate solder joint reliability under certain end-use conditions. Wherever the test results are not readily available, a fine-tuned and well-benchmarked modeling methodology is of significance in producing quick-turn judgments and risk assessments to expedite product development. The two most critical elements in simulating solder joint reliability are 1) the solder constitutive equations, which describe the solder creep behavior under different working conditions, and 2) the fatigue model which ties the damage index from finite element modeling together with the experimental results. In this study, a novel approach has been explored in which the constants of the constitutive equation and fatigue model for Sn-based Pb-free solder joints were derived inversely based on ATC results of a ceramic BGA test vehicle. In order to cover the typical end-use conditions of the targeted products, the test vehicle was assembled onto PCBs with two different thicknesses and then thermal cycled under three different temperature profiles. The basic idea was that all of the constants, both for the constitutive equation and the fatigue life prediction model, were initially given as a range. Then by utilizing modeFrontier®, a multi-objective optimization software, the finite-element model was coupled with the virtual optimization algorithm to derive simultaneously all the constants that yielded the best fatigue life predictions compared to the test results. To simplify the problem without compromising the generality, a hyperbolic sine creep constitutive equation and Coffin-Manson fatigue model were selected in the analysis. There were a total of 6 constants to be determined; the initial ranges of the constants were defined by fitting the creep experimental data for a variety of Sn-based solder materials. Available in other publications, the selected solder materials cover a wide range of both Ag and Cu content which therefore represent the typical behavior of the most commonly adopted solder materials by the industry. To reduce the computational cost and enable fast convergence of multiple-generation iterations required by the multiple objective optimization algorithms, a very-well benchmarked submodel has been employed. Furthermore, by utilizing ANSYS® high performance computing (HPC) capability and cloud computing, the computational time was reduced significantly. An overall good correlation was achieved between the fatigue life prediction using the constants derived by this approach and the test characteristic life.

Microstructural evolution and interfacial reactions of fluxless-bonded Au-20Sn/Cu solder joint during reflow and aging

2007 ◽  
Vol 22 (10) ◽  
pp. 2817-2824 ◽  
Author(s):  
Jeong-Won Yoon ◽  
Hyun-Suk Chun ◽  
Hoo-Jeong Lee ◽  
Seung-Boo Jung
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Intermetallic Compound ◽  
Solder Joint ◽  
Microstructural Evolution ◽  
Surface Finish ◽  
Solder Matrix ◽  
Interfacial Reactions ◽  
Cu Substrate ◽  
Study Results

The microstructural evolution and interfacial reactions of fluxless-bonded, Au-20wt%Sn/Cu solder joint were investigated during reflow and aging. After reflowing at 310 °C, only one thick and irregularly shaped ζ(Cu) layer was formed at the interface. After the prolonged reflow reaction, the AuCu layer was formed between the ζ(Cu) layer and the Cu substrate. During reflowing, the Cu substrate reacted primarily with the ζ-phase in the solder matrix. The solid-state interfacial reaction was much faster at 250 °C than at 150 °C. After aging at 250 °C for 100 h, thick ζ(Cu), AuCu and AuCu3 IMC layers were formed at the interface. The formation of the AuCu3 intermetallic compound (IMC) was caused by Cu enrichment at the AuCu/Cu layer interface. After aging for 500 h, cracks were observed inside the interfacial AuCu layer. The study results clearly demonstrate the need for an alternative surface finish on Cu, to ensure the high temperature reliability of the Au-20Sn/Cu solder joint.

scholarly journals Thermal Cycling Test and Simulation of Fan-Out Chip-Last Panel-Level Packaging for Heterogeneous Integration

2021 ◽  
Vol 18 (2) ◽  
pp. 29-39
Author(s):  
John H Lau ◽  
Cheng-Ta Ko ◽  
Chia-Yu Peng ◽  
Kai-Ming Yang ◽  
Tim Xia ◽  
...  
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Circuit Board ◽  
Heterogeneous Integration ◽  
Thermal Cycling Test ◽  
Test Results ◽  
Solder Joint Reliability ◽  
Cycling Test ◽  
Pcb Assembly ◽  
Joint Reliability

Abstract In this study, the reliability of the solder joints of a heterogeneous integration of one large chip (10 × 10 mm) and two smaller chips (7 × 5 mm) by a fan-out method with a redistribution layer-first substrate fabricated on a 515 × 510-mm panel is investigated. Emphasis is placed on the thermal cycling test (−55°C Δ 125°C, 50-min cycle) of the heterogeneous integration package on a printed circuit board (PCB). The thermal cycling test results are plotted into a Weibull distribution. The Weibull slope and characteristic life at median rank are presented. At 90% confidence, the true Weibull slope and the true 10% life interval are also provided. A linear acceleration factor is adopted to map the solder joint reliability at the test condition to the solder joint reliability at an operating condition. The failure location and failure mode of the PCB assembly of the heterogeneous integration package are provided and discussed. A nonlinear, time- and temperature-dependent 3-D finite element simulation is performed for the heterogeneous integration PCB assembly and correlated with the thermal cycling test results.

Microstructure, Wettability and IMC Formation of Low-Ag SAC Solder on Cu Substrate

2014 ◽  
Vol 1024 ◽  
pp. 223-226
Author(s):  
Maslinda Kamarudin ◽  
Mohd Sharif Nurulakmal ◽  
Abu Seman Anasyida
Keyword(s):  
Solder Joint ◽  
Grain Boundaries ◽  
Thermal Aging ◽  
Detrimental Effect ◽  
Bulk Solder ◽  
Solder Alloys ◽  
Sac305 Solder ◽  
Cu Substrate ◽  
Solder Microstructure ◽  
Sac Solder

This Paper Reports the Microstructure, IMC Evaluation and Wettability of Low-Ag Sn-Ag-Cu(SAC) (0.3 Wt% Ag and 0.5 Wt% Ag) and SAC305 Solder Alloys in Reflowed and Agedconditions. Reflow was Done at 250°C and Thermal Aging at 150°C For100 Hours. Microstructure of Bulk Solder and the IMC Formed at Interfacebetween Solder and Cu Substrate were Observed Using SEM Equipped with EDX. Microstructureobservation Showed Finer β-Sn Dendrites at 0.3%Ag Indicating a Possiblerefining Effect of Lower Ag on Bulk Solder Microstructure. SEM Result Showedfiner Ag3Sn Distributed in the Solder but the IMC Thickness of Bothreflowed and Aged Solder Joint Seems to Increase with Decreasing Ag Content.This could be due to Finer β-Sn Dendrites which Provide more Diffusion Paththrough Grain Boundaries and Increase IMC Thickness. Similarly, Lower Ag Content Appears to have Detrimental Effect on Wettability and Wetting Angle Ofsolder Joint.

Interfacial Reactions between Sn-Ag-Cu-Fe Composite Solder and Cu Substrate

2013 ◽  
Vol 706-708 ◽  
pp. 138-141
Author(s):  
Xiao Ying Liu ◽  
Ming Liang Huang ◽  
Ning Zhao
Keyword(s):  
Intermetallic Compound ◽  
Solder Joint ◽  
Growth Kinetics ◽  
Liquid State ◽  
Composite Solder ◽  
Interfacial Reactions ◽  
The Other ◽  
Cu Substrate ◽  
Soldering Process ◽  
Small Cracks

The growth kinetics and morphology of intermetallic compound (IMC) between Sn-3Ag-0.5Cu -xFe (x= 0, 0.5wt.%, 1wt.%) composite solders and Cu substrate were investigated in the present work. The Sn-Ag-Cu-Fe/Cu solder joint were prepared by reflowing for various durations at 250°C. During soldering process, Fe particles quickly deposited in the vicinity of IMC, resulting in the formation of Fe-rich area. It was shown that Fe could effectively retard the growth of interfacial Cu6Sn5 and Cu3Sn layers during liquid-state reaction and reduce the size of Cu6Sn5 grains. Small cracks were observed in the Cu6Sn5 grains of Sn-Ag-Cu/Cu interface after reflowing for 30 min while they were not found in the other composite solders.

Effect of Cu content on the mechanical reliability of Ni/Sn–3.5Ag system

2007 ◽  
Vol 22 (3) ◽  
pp. 770-776 ◽  
Author(s):  
J.Y. Kim ◽  
Y.C. Sohn ◽  
Jin Yu
Keyword(s):  
Solder Joint ◽  
Shear Test ◽  
Test Results ◽  
Under Bump Metallization ◽  
Mechanical Reliability ◽  
Ball Shear ◽  
Cu Content ◽  
Joint Microstructure ◽  
Ball Shear Test ◽  
Solder Joint Microstructure

Copper was supplied to Sn–3.5Ag by electroplating Cu/Ni double under-bump metallization (UBM), and the amount of Cu was controlled by varying the Cu UBM thickness. Supposed Cu contents in the solder were; 0.2, 0.5, and 1.0 wt%, respectively, and the solder joint microstructure was investigated after 1, 5, and 10 reflows. In the case of specimens with 0.2 and 1.0 wt% Cu, only one type of intermetallic compound (IMC) formed, either (Cu,Ni)6Sn5 or (Ni,Cu)3Sn4, while two types formed in specimen with 0.5 wt% Cu. No correlation could be found between the solder joint microstructure and the ball shear test. However, drop test results showed two opposite trends. The drop resistance of 0.2 and 1.0 wt% Cu specimens was quite good initially but degraded dramatically with multiple reflows, in contrast to that of the 0.5 wt% Cu specimen, which was very poor after one reflow but improved substantially later on. The former was ascribed to thickening of IMC during reflow, while the latter was related to (Ni,Cu)3Sn4 thickening beneath (Cu,Ni)6Sn5 and subsequent spalling of (Cu,Ni)6Sn5 from (Ni,Cu)3Sn4.

Effect of Multiple Reflows on the Mechanical Reliability of Solder Joint in LED Package

2010 ◽  
Vol 48 (11) ◽  
pp. 1035-1040 ◽  
Author(s):  
Young-Chul Lee ◽  
Kwang-Seok Kim ◽  
Ji-Hyuk Ahn ◽  
Jeong-Won Yoon ◽  
Min-Kwan Ko ◽  
...  
Keyword(s):  
Solder Joint ◽  
Mechanical Reliability
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