Solder Joint Technology: Materials, Properties, and Reliability

ISBN-13: 9780387388908 / Angielski / Twarda / 2007 / 370 str.

King-Ning Tu

Opis

Solder joints are ubiquitous in electronic consumer products. The European Union has a directive to ban the use of Pb-based solders in these products on July 1^st, 2006. There is an urgent need for an increase in the research and development of Pb-free solders in electronic manufacturing. For example, spontaneous Sn whisker growth and electromigration induced failure in solder joints are serious issues. These reliability issues are quite complicated due to the combined effect of electrical, mechanical, chemical, and thermal forces on solder joints. To improve solder joint reliability, the science of solder joint behavior under various driving forces must be understood. In this book, the advanced materials reliability issues related to copper-tin reaction and electromigration in solder joints are emphasized and methods to prevent these reliability problems are discussed.

Spis treści

Introduction. -Surface mount technology, pin-through-hole technology, & flip chip technology. -Reliability issues of solder joints: spalling, low cycle fatigue, electromigration, ductile-to-brittle transition in impact, Sn whisker. -Trend in electronic packaging: Chip-packaging interaction, more IMC formation in smaller solder joints. -Cu-Sn reaction in bulk samples. -Wetting reaction in bulk samples of eutectic SnPb on Cu foil. -Ternary phase diagram of Sn-Pb-Cu. -Wetting reaction in bulk samples of Pb-free solders on Cu foil . -Solid state reaction in bulk samples of eutectic SnPb on Cu foil. -Solid state reaction in bulk samples of Pb-free on Cu foil. -Comparison between wetting and solid state reactions. -Cu-Sn reaction in thin film samples. -Room temperature reaction in bimetallic thin films of Sn and Cu. -Wetting reaction of molten SnPb solders on thin films of Au/Cu/Cr. -Spalling of Cu-Sn IMC. -Wetting reaction of molten eutectic SnPb on thin films of Cu/Ni(V)/Al. -Wetting tip reaction. -Cu-Sn reaction in flip chip solder joints and electromigration. -Processing a flip chip solder joint. -Thick film UBM of electroless Ni(P), electrolytic Ni. -Very thick Cu under-bump metallization and Cu bond-pack. -Interaction between UBM and bond-pad; Effect of Ni on (Cu,Ni)Sn IMC formation across a flip chip solder joints. -Reaction in composite solder joints. -Thermal stress across flip chip solder joint. -Effect of electromigration and current crowding. -Kinetic analysis of flux-driven ripening of Cu-Sn scallops. -Theory of non-conservative ripening with a constant surface area and increasing volume with time. -Size and orientation distribution of scallops. -Nano channels between scallops. -Polarity effect of electromigration on solder reactions. -V-groove samples. -Parabolic growth of IMC at the anode. -Dissolution of Cu and dynamic equilibrium at the cathode. -Critical product and back stress. -Narrow current density range. -Diffusivity of Pb and Sn as a function of temperature. -Ductile–to-brittle transition of solder joints affected by Cu-Sn reactions. -One-dimensional samples. -Tensile, shear, and creep tests. -Impact test. -Ductile-to-brittle transition. -Spontaneous Sn whisker growth on Cu leadframe finished with Pb-free. -Irreversible processes in Sn whisker growth. -Mechanism of compressive stress generation and relaxation. -Prevention of Sn whisker growth. -Comparison to solder reactions on other metals. -Solder reactions on Ni. -Solder reactions on Au. -Solder reactions on Pd (A ring sample was used to avoid wetting tip spread). -Sn-Zn solder on Cu.

O autorze

Solder joints are ubiquitous in electronic consumer products. With the European Union s directive to ban the use of lead-based (Pb) solders in these products, there is an urgent need for research on solder joint behavior under various driving forces in electronic manufacturing, and for development of lead-free solders. For example, spontaneous Sn whisker growth and electromigration-induced failure in solder joints are serious issues. Analyzing and improving reliability is quite complicated due to the combined effects of electrical, mechanical, chemical, and thermal forces on solder joints. This book thoroughly examines advanced materials reliability issues related to copper-tin reaction and electromigration in solder joints, and presents methods to prevent common reliability problems.