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Article
Recrystallization as a Growth Mechanism for Whiskers on Plastically Deformed Sn Films
Sn whiskers are becoming a serious reliability issue in Pb-free electronic packaging applications. Sn whiskers are also observed in connector parts of electronics as well as on electroplated surface finishes. ...
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Article
Effects of Sodium Citrate Concentration on Electroless Ni-Fe Bath Stability and Deposition
In this research, electroless Ni-Fe bath stability and deposition characteristics were investigated for various sodium citrate concentrations. Complexing agents such as sodium citrate are one of the main compo...
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Article
Investigation of Sn Whisker Growth in Electroplated Sn and Sn-Ag as a Function of Plating Variables and Storage Conditions
Sn whiskers are becoming a serious reliability issue in Pb-free electronic packaging applications. Among the numerous Sn whisker mitigation strategies, minor alloying additions to Sn have been proven effective...
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Article
Electromigration performance of Pb-free solder joints in terms of solder composition and joining path
The electromigration (EM) performance of Pb-free solder joints is investigated in terms of solder composition (Sn-0.5Cu vs. Sn-1.8Ag) and joining path to Cu vs. Ni(P) under bump metallization (UBM). In the dou...
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Article
Foreword
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Article
The Crystal Orientation of β-Sn Grains in Sn-Ag and Sn-Cu Solders Affected by Their Interfacial Reactions with Cu and Ni(P) Under Bump Metallurgy
Recently, it has been reported that the crystal orientation and grain size of the β-Sn phase in Sn-rich solders have profound effects on the reliabilities of Pb-free solder joints, such as thermo-mechanical fa...
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Article
Interfacial Reactions and Microstructures of Sn-0.7Cu-xZn Solders with Ni-P UBM During Thermal Aging
The effects of the addition of Zn to Sn-0.7Cu solders are investigated. The study is focused on the interfacial reactions, microstructures, and mechanical properties after reaction with Ni-P under bump metallu...
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Article
An Investigation of Microstructure and Microhardness of Sn-Cu and Sn-Ag Solders as Functions of Alloy Composition and Cooling Rate
The microstructure and microhardness of Sn-xAg and Sn-xCu solders were investigated as functions of alloy composition and cooling rate. The Ag compositions examined varied from 0.5 wt.% to 3.5 wt.%, while Cu vari...
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Article
Effects of under bump metallization and nickel alloying element on the undercooling behavior of Sn-based, Pb-free solders
A significant reduction of the undercooling of Sn-based solder alloys was previously reported when they were reacted with various under bump metallurgies (UBMs). In the present study, new experiments have been...
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Article
An overview of Pb-free, flip-chip wafer-bum** technologies
To meet the European Union Restriction of Hazardous Substances requirements and the continuing demand for lower costs, finer pitch, and high-reliability flip-chip packaging structures, considerable work is goi...
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Article
Undercooling and microhardness of Pb-free solders on various under bump metallurgies
The undercooling behavior of pure Sn, Sn–0.7Cu, Sn–3.5Ag, and Sn–3.8Ag–0.7Cu solder alloys was observed in terms of various under bump metallurgies (UBMs). Four different UBMs (electroplated Cu, electroplated ...
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Article
Effects of Minor Additions of Zn on Interfacial Reactions of Sn-Ag-Cu and Sn-Cu Solders with Various Cu Substrates during Thermal Aging
The effects of Zn additions to Sn-0.7Cu and Sn-3.8Ag-0.7Cu (all in wt.% unless specified otherwise) Pb-free solders on the interfacial reactions with Cu substrates were investigated. The study was focused on t...
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Article
Study of the undercooling of Pb-free, flip-chip solder bumps and in situ observation of solidification process
The undercooling of flip-chip Pb-free solder bumps was investigated by differential scanning calorimetry (DSC) to understand the effects of solder composition and volume, with and without the presence of an un...
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Article
Foreword
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Article
Interfacial reactions of Sn-Ag-Cu solders modified by minor Zn alloying addition
The near-ternary eutectic Sn-Ag-Cu alloys have been identified as leading Pb-free solder candidates to replace Pb-bearing solders in microelectronic applications. However, recent investigations on the processi...
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Article
The oxidation of lead-free Sn alloys by electrochemical reduction analysis
The oxidation of pure tin and Sn-0.7Cu, Sn-3.5Ag, Sn-1Zn, and Sn-9Zn alloys at 150°C was investigated. Both the chemical nature and the amount of oxides were characterized using electrochemical reduction analy...
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Article
Oxidation study of pure tin and its alloys via electrochemical reduction analysis
The oxidation of pure Sn and high Pb-Sn alloys was investigated under different oxidizing conditions of temperature and humidity. Both the chemical nature and the amount of oxides were characterized using elec...
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Article
Foreword
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Article
Controlling Ag3Sn plate formation in near-ternary-eutectic Sn-Ag-Cu solder by minor Zn alloying
As a result of extensive studies, nearternary-eutectic Sn-Ag-Cu (SAC) alloys have been identified as the leading lead-free solder candidates to replace lead-bearing solders for ball-grid array module assembly....
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Article
The microstructure of Sn in near-eutectic Sn–Ag–Cu alloy solder joints and its role in thermomechanical fatigue
During the solidification of solder joints composed of near-eutectic Sn–Ag–Cu alloys, the Sn phase grows rapidly with a dendritic growth morphology, characterized by copious branching. Notwithstanding the comp...
