Nanoparticle Enhanced Solders for Increased Solder Reliability

2012 ◽  
Vol 1424 ◽  
Author(s):  
Omid Mokhtari ◽  
Ali Roshanghias ◽  
Roya Ashayer ◽  
Hiren R Kotadia ◽  
Farzad Khomamizadeh ◽  
...  

AbstractDue to environmental concerns traditional eutectic tin-lead solder is gradually being replaced in electronic assemblies by “lead-free” solders. During this transition, nanoparticle technology is also being investigated to see whether improvements in joint reliability for high temperature applications can be made. Nanoparticles can be used to harden the solder via Zener pinning of the grain boundaries and reduce fatigue failure. This paper explores the effects of adding Silica nanoparticles to SnAgCu solder, and how the mechanical properties induced in the solder vary with temperature. It is found that above 100 °C the mechanical response and microstructure of the normal and nanoparticle enhanced solders converge.

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Lei Sun ◽  
Liang Zhang

SnAgCu solder alloys were considered as one of the most popular lead-free solders because of its good reliability and mechanical properties. However, there are also many problems that need to be solved for the SnAgCu solders, such as high melting point and poor wettability. In order to overcome these shortcomings, and further enhance the properties of SnAgCu solders, many researchers choose to add a series of alloying elements (In, Ti, Fe, Zn, Bi, Ni, Sb, Ga, Al, and rare earth) and nanoparticles to the SnAgCu solders. In this paper, the work of SnAgCu lead-free solders containing alloying elements and nanoparticles was reviewed, and the effects of alloying elements and nanoparticles on the melting temperature, wettability, mechanical properties, hardness properties, microstructures, intermetallic compounds, and whiskers were discussed.


2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal

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.  


2008 ◽  
Vol 18 (4) ◽  
pp. 814-818 ◽  
Author(s):  
Zong-jie HAN ◽  
Song-bai XUE ◽  
Jian-xin WANG ◽  
Xin ZHANG ◽  
Liang ZHANG ◽  
...  

2010 ◽  
Vol 2010 (1) ◽  
pp. 000314-000318
Author(s):  
Tong Jiang ◽  
Fubin Song ◽  
Chaoran Yang ◽  
S. W. Ricky Lee

The enforcement of environmental legislation is pushing electronic products to take lead-free solder alloys as the substitute of traditional lead-tin solder alloys. Applications of such alloys require a better understanding of their mechanical behaviors. The mechanical properties of the lead-free solders and IMC layers are affected by the thermal aging. The lead-free solder joints on the pads subject to thermal aging test lead to IMC growth and cause corresponding reliability concerns. In this paper, the mechanical properties of the lead-free solders and IMCs were characterized by nanoindentation. Both the Sn-rich phase and Ag3Sn + β-Sn phase in the lead-free solder joint exhibit strain rate depended and aging soften effect. When lead-free solder joints were subject to thermal aging, Young's modulus of the (Cu, Ni)6Sn5 IMC and Cu6Sn5 IMC changed in very small range. While the hardness value decreased with the increasing of the thermal aging time.


Author(s):  
M. Faizan ◽  
R. A. McCoy ◽  
D. C. Lin ◽  
G.-X. Wang

Copper dissolution and intermetallic compound (IMC) formation during reflow of soldered joints are critical issues for joint reliability. Most of studies in the literature aimed at the coarsening and growth of the IMC layer of the soldered joints during service and only limited data is available during soldering process. This is particularly true for lead-free solders, which have attracted the attention of researchers just recently. This paper presents an experimental study of copper dissolution and IMC growth of lead-free solders during the reflow process. Solder buttons of either Sn or Sn-3.5wt%Ag were reflowed over a copper (99.9% pure) substrate for various reflow time periods ranging from 10 seconds to 10 minutes. Four reflow temperatures were selected, 232°C, 250°C, 275°C and 300°C for pure tin and 221°C, 250°C, 275°C and 300°C for Sn-3.5%Ag respectively. The average thickness of the grown IMC layer and the amount of copper dissolved during reflow were determined using the images obtained from the metallurgical microscope. The kinetics of IMC growth and Cu dissolution were then quantified and the estimated kinetics parameters can be used to determine the copper dissolution and IMC layer thickness during reflow soldering.


2003 ◽  
Vol 18 (7) ◽  
pp. 1528-1534 ◽  
Author(s):  
Chia-Wei Huang ◽  
Kwang-Lung Lin

The microstructure, melting point, and mechanical properties of Sn–8.55Zn–0.45Al–XAg lead-free solders were investigated. The Ag content of the solders investigated was 0–3 wt.%. The results indicate that the AgZn3 and Ag5Zn8 compounds are formed at the addition of Ag to Sn–8.55Zn–0.45Al solders. The adding of Ag also results in the formation of hypoeutectic structure, increasing the melting point of the solders and decreasing the ductility. Results of thermal analysis reveal that the Sn–8.55Zn–0.45Al–XAg solder has eutectic temperature at 198 °C when the addition of Ag is 0.5 wt.%. The eutectic solder exhibits greater tensile strength and higher ductility than the 63–Sn–37Pb solder.


2016 ◽  
Vol 857 ◽  
pp. 3-7 ◽  
Author(s):  
Ramani Mayappan ◽  
Nur Nadiah Zainal Abidin ◽  
Noor Asikin Ab Ghani ◽  
Iziana Yahya ◽  
Norlin Shuhaime

Due to environmental concerns, lead-free solders were introduced to replace the lead-based solders in microelectronics devices technology. Although there are many lead-free solders available, the Sn-Ag-Cu solders are considered the best replacement due to their good wettability and joint strength. Although the Sn-Ag-Cu solders are accepted widely, but there are still some room for improvement. In this study, 1wt% Zn, which can be considered high percentage for a dopant, was added into the solder via powder metallurgy route. The effects of adding this dopant into the Sn-3.5Ag-1.0Cu solder on the interface intermetallic and thickness were investigated. The intermetallics phases formed were observed under Scanning Electron Microscope (SEM) and their thicknesses were measured. The SEM results showed the presence of Cu6Sn5, Cu3Sn and (Cu,Zn)6Sn5 intermetallics. It can be concluded that Zn behaved as retarding agent and significantly retarded the growth of Cu-Sn intermetallics.


Author(s):  
M. Pei ◽  
J. Qu

Solders are used extensively as electrical interconnects in microelectronics packaging. Because of environmental concerns, lead-based solders are being replaced by Sn/Ag and Sn/Ag/Cu based solder materials. Since the thermomechanical reliability of modern electronic devices depends on, to a large extent, the fatigue and creep behavior of the solder joints, it is imperative to understand the deformation behavior of these new lead-free solders. This study conducted extensive thermomechanical testing on several commercial lead-free solder alloys. Anand viscoplastic model was used to describe the behavior of these materials with new curve fitting techniques. A modified Anand models was proposed that can yield a more accurate description of lead-free solders.


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