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
Development of a lead-free composite solder from Sn–Ag–Cu and Ag-coated carbon nanotubes
TL;DR: In this article, composites with Agcoated single-walled carbon nanotubes (Ag-coated SWCNTs) were incorporated into 96.5Sn-3.5Cu solder alloy with an ultrasonic mixing technique.
Journal ArticleDOI
Effects of Co Alloying and Size on Solidificationand Interfacial Reactions in Sn-57 wt.%Bi-(Co)/Cu Couples
Yu-chih Huang,Sinn-wen Chen +1 more
TL;DR: In this article, the authors investigated solidification and interfacial reactions in Sn-57 wt.%Bi-(Co)/Cu couples and found that the addition of 0.05 wt % Co and 0.5 wt% Co and changes between 2 g and 20 mg solder sizes have no significant effects on the undercooling of Sn- 57 wt.%Bi solders.
Journal ArticleDOI
Inhibition of interfacial embrittlement at SnBi/Cu single crystal by electrodeposited Ag film
TL;DR: In this paper, Electrodeposited Ag film was explored as a potential interfacial barrier to Bi segregation for suppressing the interfacial embrittlement of Cu/SnBi interconnects.
Journal ArticleDOI
Fluxless Sn–Ag bonding in vacuum using electroplated layers
Jongsung Kim,Chin C. Lee +1 more
TL;DR: In this article, a fluxless bonding process in vacuum environment using newly developed electroplated Sn-Ag multilayer structure at eutectic composition is presented, in which the oxygen content is reduced by a factor of 7600 comparing to air, to inhibit solder oxidation.
Journal ArticleDOI
Thermodynamic Optimization of Bi-Ni Binary System
TL;DR: In this paper, the intermetallic compound, BiNi, was modeled using three sublattices (Bi) (Ni, Va) and the compatibility of thermodynamic database in the multi-component systems, while Bi3Ni was treated as a stoichiometric compound.
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