Journal ArticleDOI
Lead-free Solders in Microelectronics
Mulugeta Abtew,Guna S Selvaduray +1 more
Reads0
Chats0
TLDR
The most widely used Pb-free solders have the eutectic composition as mentioned in this paper, which has been identified as a major factor affecting alloy selection, since this will have a major impact on the other polymeric materials used in microelectronic assembly and encapsulation.Abstract:
Practically all microelectronic assemblies in use today utilize Pb–Sn solders for interconnection. With the advent of chip scale packaging technologies, the usage of solder connections has increased. The most widely used Pb–Sn solder has the eutectic composition. Emerging environmental regulations worldwide, most notably in Europe and Japan, have targeted the elimination of Pb usage in electronic assemblies, due to the inherent toxicity of Pb. This has made the search for suitable “Pb-free” solders an important issue for microelectronics assembly. Approximately 70 Pb-free solder alloy compositions have been proposed thus far. There is a general lack of engineering information, and there is also significant disparity in the information available on these alloys. The issues involved can be divided into two broad categories: manufacturing and reliability/performance. A major factor affecting alloy selection is the melting point of the alloy, since this will have a major impact on the other polymeric materials used in microelectronic assembly and encapsulation. Other important manufacturing issues are cost, availability, and wetting characteristics. Reliability related properties include mechanical strength, fatigue resistance, coefficient of thermal expansion and intermetallic compound formation. The data available in the open literature have been reviewed and are summarized in this paper. Where data were not available, such as for corrosion and oxidation resistance, chemical thermodynamics was used to develop this information. While a formal alloy selection decision analysis methodology has not been developed, less formal approaches indicate that Sn-rich alloys will be the Pb-free solder alloys of choice, with three to four alloys being identified for each of the different applications. Research on this topic continues at the present time at a vigorous pace, in view of the imminence of the issue.read more
Citations
More filters
Journal ArticleDOI
Effects of Ag particles content on properties of Sn0.7Cu solder
TL;DR: In this paper, the effects of Ag particle contents on spreadability, microstructure, shear strength and creep rupture life of Sn0.7Cu solders have been studied.
Journal ArticleDOI
Phase equilibria of the Sn-Ag-Cu-Ni quaternary system at the sn-rich corner
Sinn-wen Chen,Cheng-A N. Chang +1 more
TL;DR: In this paper, the phase equilibrium of the Sn-Ag-Cu-Ni quaternary system at the Snrich corner was determined by metallography, compositional analysis, and x-ray diffraction (XRD) analysis.
Journal ArticleDOI
Effect of temperature and alloying elements (Fe and Bi) on the electrical resistivity of Sn–0.7Cu solder alloy
Hasan Abbas Jaffery,Mohd Faizul Mohd Sabri,Shaifulazuar Rozali,Mohammad Hossein Mahdavifard,Dhafer Abdulameer Shnawah +4 more
TL;DR: In this article, the authors investigated the electrical resistivity as a function of temperature of the Sn-0.7Cu solder alloy with the addition of Fe and Bi. The electrical resistivities were characterized by the four-point probe method, which revealed the presence of Sn in Sn2+, Sn4+ and state of metallic Sn.
Journal ArticleDOI
Thermophysical properties of liquid tin–bismuth alloys
TL;DR: In this paper, the electrical and thermal conductivity, viscosity, surface tension and density were studied in a wide temperature range above the liquidus, and scaling relations have been proposed.
Journal ArticleDOI
Effect of TiO 2 addition concentration on the wettability and intermetallic compounds growth of Sn3.0Ag0.5Cu–xTiO 2 nano-composite solders
TL;DR: In this paper, the effect of adding TiO2 nanoparticles with a concentration in the range from 0 to 0.75% into eutectic Sn3.0Ag0.5Cu solders was investigated.
References
More filters
Journal ArticleDOI
Quantitative assessment of worldwide contamination of air, water and soils by trace metals
Jerome O. Nriagu,Jozef M. Pacyna +1 more
TL;DR: Calculated loading rates of trace metals into the three environmental compartments demonstrate that human activities now have major impacts on the global and regional cycles of most of the trace elements.
Book
Principles and prevention of corrosion
TL;DR: In this article, the technology and evaluation of Corrosion is presented, with a focus on the effects of Metallurgical Structure on Corrosions, and a discussion of materials selection and design.
Book
Physical Metallurgy Principles
TL;DR: Physical Metallurgy Principles as mentioned in this paper is intended for use in an introductory course in physical metallurgy and is designed for all engineering students at the junior or senior level and is largely theoretical, but covers all aspects of physical metelurgy and behavior of metals and alloys.
Journal ArticleDOI
Interdiffusion and Reaction in Bimetallic Cu-Sn Thin Films
TL;DR: In this article, a Seemann-Bohlin diffractometer was used to investigate interdiffusion and intermetallic compound formation in Cu-Sn thin film couples.
Related Papers (5)
Six cases of reliability study of Pb-free solder joints in electronic packaging technology
Kejun Zeng,King-Ning Tu +1 more