There has been major interest in Lead-free soldering within the electronics assembly industry for the last several years, and this will continue with the agreement on the language and implementation dates of the WEEE/ROHS legislation in the EU. This paper will focus on several topics critical to the implementation of lead-free soldering. These topics include the impact of Tin-silver-copper as t...

Young’s modulus (E) values published in the literature for the eutectic Pb37/Sn63 and near eutectic Pb40/Sn60 solder alloy vary significantly. One reason for this discrepancy is different testing methods for highly rate sensitive heterogeneous materials, like Pb/Sn alloys, yield different results. In this paper, we study different procedures used to obtain the elastic modulus; analytically, by ...

A solder fatigue model for the 63Sn/Pb solder alloy has been previously introduced which characterizes the creep fatigue phenomena of the solder by combining nonlinear finite element modelling with experimental thermal fatigue lives of various flip chip assemblies. The model correlates the amount of creep strain energy dissipated per thermal cycle with the characteristic Weibull life of the cri...

The processes of melt formation were studied by methods optical and electron scanning microscopy. These occur during induction brazing a hard alloy to steel holder contact interaction low-melting (copper-zinc system alloy) refractory (iron-nickel) components the solders. It is shown that effect thermal magnetic-dynamic high-frequency electromagnetic field on composite solder how high-strength j...

High-end microelectronic packaging is increasingly moving from wire bonds to solder bumps as the method of interconnection. There are various solder bumping technologies used in volume production. These include electroplating, solder paste printing, evaporation and the direct attach of preformed solder spheres. Flip chip in Package (FCiP) requires many small bumps on tight pitch whereas Wafer L...

In this study, interfacial reactions of electrolytic Ni and electroless Ni(P) metallization of the ball-grid-array (BGA) substrate with the molten n–9Zn (wt.%) eutectic solder alloy were investigated, focusing on the shear strengths and the identification of the intermetallic compound IMC) phases at various reflow periods. Zn-containing Pb-free solder alloys were kept in molten condition (240 ◦...

The integration and miniaturization trend of the electronic packaging leads to much finer pitch of the device and package lead terminations. Several reliability concerns and issues that were previously not encountered are now surfacing. The objective of this thesis work is to investigate the reliability of the package-to-board interconnection from the perspective of solder joint metallurgy. It ...

The reliability of Pb-free solder joints is controlled by their microstructural constituents. Therefore, knowledge of the solder microconstituents' mechanical properties as a function of temperature is required. Sn-Ag-Cu lead-free solder alloy contains three phases: a Sn-rich phase, and the intermetallic compounds (IMCs) CueSn5 and Ag3Sn. Typically, the Sn-rich phase is surrounded by a eutectic...

The trend of miniaturization, light weight, high speed and multifunction are common in electronic assemblies, especially, for portable electronic products. In particular, board-level solder joint reliability, in term of both mechanical (e.g., drop impact) and thermo-mechanical (e.g., thermal cycling) loads is of great concern for portable electronic products. The transition to lead-free solder ...

Alloy Al – 27% Cu – 6% Si has a composition close to an eutectic one [1, 2] and is widely used as a solder (A34) for soldering aluminum and its alloys [3]. The main problem in fabrication of cast solder A34 is the formation of a ternary ( + CuAl 2 + Si) eutectic and primary silicon crystals in its structure, which lowers substantially the process and operating properties of the alloys. It is kn...