This thesis presents a series of mechanical test methods and comprehensively investigates the deformation and damage behavior of Cu/Pb-free solder joints under different loading conditions. The fracture behavior of Pb-free joint interfaces induced by stress, deformation of solder and substrate are shown, the shear fracture strength of the Cu6Sn5 IMC is measured experimentally for the first time, and the dynamic damage process and microstructure evolution behavior of Pb-free solder joints are revealed intuitively. The thesis puts forward the argument that the local cumulative damage is the major cause of failure in solder joints. The research results provide the experimental and theoretical basis for improving the reliability of solder joints.

Although Sn-Pb eutectic alloy is widely used as a joining material in the electronics industry, it has well documented environmental and toxicity issues. Sandia National Laboratories is developing alternative solder materials to replace traditional Pb-containing alloys. The alloys are based on the Sn-Ag, Sn-Ag-Bi and Sn-Ag-Bi-Au systems. Prototype hybrid microcircuit (HMC) test vehicles have been developed to evaluate these Pb-free solders, using Au-Pt-Pd thick film metallization. Populated test vehicles with surface mount devices have been designed and fabricated to evaluate the reliability of surface mount solder joints. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCCC's). Intermetallic compound (IMC) layer reaction products that form at the solder/substrate interface have been characterized and their respective growth kinetics quantified. Thicker IMC layers pose a potential reliability problem with solder joint integrity. Since the IMC layer is brittle, the likelihood of mechanical failure of a joint in service is increased. The effect of microstructure and the response of these different materials to wetting, aging and mechanical testing was also investigated. Solid-state reaction data for intermetallic formation and mechanical properties of the solder joints are reported.

The book presents select proceedings of the International Conference on Materials, Design and Manufacturing (ICMDMSE 2022). The book covers recent trends in design and manufacturing practices relating to sustainability. Various topics covered in this book include materials design for sustainability, material characterization, tribology, finite element methods (FEM), computational fluid dynamics in designing materials, manufacturing techniques inclined to sustainability, additive manufacturing, energy, Industry 4.0, MEMS, green manufacturing, and optimization techniques. This book will be useful for researchers and professionals working in various fields of mechanical engineering.

This book highlights recent research progress in lead (Pb)-free solder technology, focusing on materials development, processing, and performances. It discusses various Pb-free solder materials’ development, encompassing composite solders, transient liquid phase sintering, and alloying. The book also details various Pb-free solder technology processing and performances, including flux modification for soldering, laser soldering, wave soldering, and reflow soldering, while also examining multiple technologies pertaining to the rigid and flexible printed circuit board (PCB). Some chapters explain the materials characterization and modeling techniques using computational fluid dynamics (CFD). This book serves as a valuable reference for researchers, industries, and stakeholders in advanced microelectronic packaging, emerging interconnection technology, and those working on Pb-free solder.

This unique book provides an up-to-date overview of the concepts behind lead-free soldering techniques. Readers will find a description of the physical and mechanical properties of lead-free solders, in addition to lead-free electronics and solder alloys. Additional topics covered include the reliability of lead-free soldering, tin whiskering and electromigration, in addition to emerging technologies and research.

Providing a viable alternative to lead-based solders is a major research thrust for the electrical and electronics industries - whilst mechanically compliant lead-based solders have been widely used in the electronic interconnects, the risks to human health and to the environment are too great to allow continued widescale usage. Lead-free Solders: Materials Reliability for Electronics chronicles the search for reliable drop-in lead-free alternatives and covers: Phase diagrams and alloy development Effect of minor alloying additions Composite approaches including nanoscale reinforcements Mechanical issues affecting reliability Reliability under impact loading Thermomechanical fatigue Chemical issues affecting reliability Whisker growth Electromigration Thermomigration Presenting a comprehensive understanding of the current state of lead-free electronic interconnects research, this book approaches the ongoing research from fundamental, applied and manufacturing perspectives to provide a balanced view of the progress made and the requirements which still have to be met.