Journal ArticleDOI
Lead-free Solders in Microelectronics
Mulugeta Abtew,Guna S Selvaduray +1 more
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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
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Journal ArticleDOI
Corrosion of Ga-doped Sn-0.7Cu Solder in Simulated Marine Atmosphere
Zhong Yan,Zhong Yan,Ai-Ping Xian +2 more
TL;DR: The surface corrosion behaviors of Sn and Sn-07Cu solder in simulated marine atmosphere have been studied in this article, where the results showed that pitting and uniform corrosion are the two main initial damage types in the corrosion process.
Journal ArticleDOI
High performance anisotropic conductive adhesives for lead‐free interconnects
Yi Li,Ching-Ping Wong +1 more
TL;DR: In this article, different types of self-assembled monolayer (SAM) compounds were introduced into the interface between the metal filler and the substrate bond pad, and the electrical properties of ACA joints containing these SAMs were studied by measuring their currentvoltage relationship.
Journal ArticleDOI
Effect of aging treatment on microstructure and creep behaviour of Sn-Ag and Sn-Ag-Bi solder alloys
TL;DR: In this article, the influence of aging temperature on the creep behavior of SnAg and SnAg-Bi solder alloys at testing temperatures ranging from 333 to 363 K under constant stress of 7·80 MPa was investigated.
Journal ArticleDOI
Microstructure, interfacial reactions and mechanical properties of Co/Sn/Co and Cu/Sn/Cu joints produced by transient liquid phase bonding
TL;DR: In this paper, the wettability and growth behaviors of interfacial intermetallic compounds (IMCs) in the Sn/Co and Sn/Cu liquid/solid couples were comparatively investigated.
Journal ArticleDOI
Low temperature Ag-Ag direct bonding under air atmosphere
TL;DR: In this article, sputtered Ag thin films were proposed as bonding materials and Ag-Ag direct bonding processes were achieved by thermo-compression process at 180-200℃ under air atmosphere in short periods.
References
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