Topics in Lead-Free Solders: Interfacial and Sn Whisker Growth

JOM ◽  
2012 ◽  
Vol 64 (10) ◽  
pp. 1174-1175 ◽  
Author(s):  
Srinivas Chada
Keyword(s):  
Whisker Growth ◽  
Lead Free ◽  
Sn Whisker ◽  
Lead Free Solders

scholarly journals Preliminary study on the effect of Ni addition on tin (Sn) whisker growth from lead-free solder coating

2020 ◽  
Vol 957 ◽  
pp. 012062
Author(s):  
Aimi Noorliyana Hashim ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Muhammad Mahyiddin Ramli ◽  
Khor Chu Yee ◽  
Noor Zaimah Mohd Mokhtar
Keyword(s):  
Whisker Growth ◽  
Lead Free ◽  
Lead Free Solder ◽  
Sn Whisker ◽  
Ni Addition ◽  
Preliminary Study ◽  
Free Solder

The influence of porosity on whisker growth in electroplated tin films

2006 ◽  
Vol 21 (12) ◽  
pp. 2971-2974 ◽  
Author(s):  
J.P. Winterstein ◽  
M.G. Norton
Keyword(s):  
Whisker Growth ◽  
Control Method ◽  
Stress Relief ◽  
Lead Free ◽  
Tin Whisker ◽  
Tin Films ◽  
The Past ◽  
Compressive Stresses ◽  
Time Period ◽  
Lead Free Solders

Tin whisker growth has been observed since the 1950s and has become of more interest in the past 15 to 20 years due to the desire to use lead-free solders, pure tin being a good lead-free candidate. In the same time period, failure of satellites and other devices using pure tin solders has been blamed on tin whisker growth. The accepted driving force for whisker growth is compressive stresses in films. This article reports a microstructure-control method of limiting whisker growth through the introduction of pores that permit an alternate means of stress relief.

Spontaneous Tin (Sn) Whisker Growth from Electroplated Tin and Lead-Free Tin Alloys Coatings: A Short Review

2018 ◽  
Vol 280 ◽  
pp. 151-156 ◽  
Author(s):  
Aimi Noorliyana Hashim ◽  
Mohd Arif Anuar Mohd Salleh
Keyword(s):  
Driving Force ◽  
Room Temperature ◽  
Whisker Growth ◽  
Copper Substrate ◽  
Short Review ◽  
Hazardous Substances ◽  
Lead Free ◽  
Sn Whisker ◽  
Tin Alloys ◽  
Sn Whiskers

Since the environmental regulations of Reduction of Hazardous Substances (RoHS) directive came into effect in Europe and Asia on July 1, 2006, requiring the removal of any lead (Pb) content from the electronics industry, the issue of tin (Sn) whisker growth from pure Sn and SnPb-free alloys has become one of the most imperative issues that need to be resolved. Moreover, with the increasing demand for electronics miniaturization, Sn whisker growth is a severe threat to the reliability of microelectronic devices. Sn whiskers grow spontaneously from an electrodeposited tin coating on a copper substrate at room temperature, which can lead to well-documented system failures in electronics industries. The Sn whisker phenomenon unavoidably gives rise to troubles. This paper briefly reviews to better understand the fundamental properties of Sn whisker growth and at the same time discover the effective mitigation practices for whisker growth in green electronic devices. It is generally accepted that compressive stress generated from the growth of Cu6Sn5 intermetallic compound (IMC) is the primary driving force for Sn whisker growth during room temperature storage. It is, therefore, important to determine that the relationship between IMC growth and Sn whisker growth. Reduction of stress in the IMC layer can therefore reduce the driving force for whisker formation and be used as a means for whisker mitigation. To date, there are no successful methods that can suppress the growth of Sn whisker as efficient as Pb addition. It is hoped that the Sn whisker growth mechanisms are understood better in the future, with better measuring and monitoring methodologies and systems being developed, the real solutions may be eventually developed to eliminate or mitigate the Sn whisker problems of green reliability lead-free electronic assemblies.

Sn whisker growth in Sn–9Zn–0.5Ga–0.7Pr lead-free solder

2011 ◽  
Vol 509 (5) ◽  
pp. L52-L55 ◽  
Author(s):  
Huan Ye ◽  
Songbai Xue ◽  
Liang Zhang ◽  
Zhengxiang Xiao ◽  
Yuhua Hu ◽  
...  
Keyword(s):  
Whisker Growth ◽  
Lead Free ◽  
Lead Free Solder ◽  
Sn Whisker ◽  
Free Solder

scholarly journals Morphology Analysis of Spontaneous Tin (Sn) Whisker Growth on Lead-Free Solder

2019 ◽  
Vol 551 ◽  
pp. 012095 ◽  
Author(s):  
Aimi Noorliyana Hashim ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Noor Zaimah Mohd Mokhtar
Keyword(s):  
Whisker Growth ◽  
Lead Free ◽  
Lead Free Solder ◽  
Sn Whisker ◽  
Morphology Analysis ◽  
Free Solder

Sn Whiskers Nucleation and Growth - Short Review

2018 ◽  
Vol 280 ◽  
pp. 175-180
Author(s):  
N. Mohd Mokhtar ◽  
Mohd Arif Anuar Mohd Salleh
Keyword(s):  
Compressive Stress ◽  
Whisker Growth ◽  
Microstructural Characterization ◽  
Short Review ◽  
Hazardous Substances ◽  
Lead Free ◽  
Whisker Formation ◽  
Sn Whisker ◽  
Sn Whiskers ◽  
Aerospace Applications

Sn whisker growth on Cu substrate Pb-free solder is a serious problem in electric and electronic devices and as well as in aerospace applications. Due to the concern on the toxicity of lead by Restriction of Hazardous Substances Directive (RoHS), new lead free materials have been developed, and this resulted in the resurfacing of Sn whisker. The compressive stress, corrosionand surface oxide have been identified as the driving force for Sn whisker formation induced by mechanical alloying and oxidation. In this paper, we report the study to understand the mechanism of Sn whisker growth that control whisker formation on Sn finished.Based on the review, a preliminary conclusion has been made, where the analysis of the topography and microstructural characterization can be determined by evaluating under various environmental influences.Furthermore, the whisker growth happening on lead-free soldered can be considerably reduced by controlling the compressive stress in the solder which initiates the growth of intermetallic compounds (IMCs).

Effect of aluminum content on structure, transport and mechanical properties of Sn-Zn eutectic lead free solder alloy rapidly solidified from melt.

2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Lead Free ◽  
Al Alloy ◽  
Lead Free Solder ◽  
Pronounced Increase ◽  
Mass Unit ◽  
Size Refinement ◽  
Free Solder ◽  
Lead Free Solders

The greatest advantage of Sn-Zn eutectic is its low melting point (198 oC) which is close to the melting point. of Sn-Pb eutectic solder (183 oC), as well as its low price per mass unit compared with Sn-Ag and Sn-Ag-Cu solders. In this paper, the effect of 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt. % Al as ternary additions on melting temperature, microstructure, microhardness and mechanical properties of the Sn-9Zn lead-free solders were investigated. It is shown that the alloying additions of Al at 4 wt. % to the Sn-Zn binary system lead to lower of the melting point to 195.72 ˚C.  From x-ray diffraction analysis, an aluminium phase, designated α-Al is detected for 4 and 5 wt. % Al compositions. The formation of an aluminium phase causes a pronounced increase in the electrical resistivity and microhardness. The ternary Sn-9Zn-2 wt.%Al exhibits micro hardness superior to Sn-9Zn binary alloy. The better Vickers hardness and melting points of the ternary alloy is attributed to solid solution effect, grain size refinement and precipitation of Al and Zn in the Sn matrix.  The Sn-9%Zn-4%Al alloy is a lead-free solder designed for possible drop-in replacement of Pb-Sn solders.  

Shear Strength and Dsc Analysis of High-Temperature Solders

2013 ◽  
Vol 58 (2) ◽  
pp. 529-533 ◽  
Author(s):  
R. Koleňák ◽  
M. Martinkovič ◽  
M. Koleňáková
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Lead Free ◽  
Dsc Analysis ◽  
Ultrasonic Activation ◽  
Metallic Substrates ◽  
Cu Substrate ◽  
Lead Free Solders

The work is devoted to the study of shear strength of soldered joints fabricated by use of high-temperature solders of types Bi-11Ag, Au-20Sn, Sn-5Sb, Zn-4Al, Pb-5Sn, and Pb-10Sn. The shear strength was determined on metallic substrates made of Cu, Ni, and Ag. The strength of joints fabricated by use of flux and that of joints fabricated by use of ultrasonic activation without flux was compared. The obtained results have shown that in case of soldering by use of ultrasound (UT), higher shear strength of soldered joints was achieved with most solders. The highest shear strength by use of UT was achieved with an Au-20Sn joint fabricated on copper, namely up to 195 MPa. The lowest average values were achieved with Pb-based solders (Pb-5Sn and Pb-10Sn). The shear strength values of these solders used on Cu substrate varied from 24 to 27 MPa. DSC analysis was performed to determine the melting interval of lead-free solders.

scholarly journals Effects of Yttrium Addition on the Microstructure Evolution and Electrochemical Corrosion of SN-9zn Lead-Free Solders Al-Loy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2549
Author(s):  
Wenchao Yang ◽  
Jun Mao ◽  
Yueyuan Ma ◽  
Shuyuan Yu ◽  
Hongping He ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Microstructure Evolution ◽  
Electrochemical Corrosion ◽  
Lead Free ◽  
Nacl Solution ◽  
Rich Phase ◽  
Yttrium Addition ◽  
Electrochemical Corrosion Behavior ◽  
Lead Free Solders ◽  
Addition Amount

Electrochemical corrosion behavior of ternary tin-zinc-yttrium (Sn-9Zn-xY) solder alloys were investigated in aerated 3.5 wt.% NaCl solution using potentiodynamic polarization techniques, and the microstructure evolution was obtained by scanning electron microscope (SEM). Eight different compositions of Sn-9Zn-xY (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, and 0.30 wt.%) were compared by melting. The experimental results show that when the content of Y reached 0.06 wt.%, the grain size of Zn-rich phase became the smallest and the effect of grain refinement was the best, but there was no significant effect on the melting point. With the increases of Y content, the spreading ratio first increased and then decreased. When the content of Y was 0.06 wt.%, the Sn-9Zn-0.06Y solder alloy had the best wettability on the Cu substrate, which was increased by approximately 20% compared with Sn-9Zn. Besides, the electrochemical corrosion experimental shows that the Y can improve the corrosion resistance of Sn-9Zn system in 3.5 wt.% NaCl solution, and the corrosion resistance of the alloy is better when the amount of Y added is larger within 0.02–0.30 wt.%. Overall considering all performances, the optimal performance can be obtained when the addition amount of Y is 0.06.

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