This tutorial references a new industry paper written by Peter Borgesen and Karl Schnabl, of Binghamton University. The flip chip world continues to evolve and devices require higher I/O, finer pitch, and improved mechanical/electrical performance. This tutorial discusses the areas where a deeper understanding of Cu Pillar and Micro Bump soldering behavior is needed.
Critical areas where “typical” soldering issues will differ are highlighted. The discussion focuses on the extremely small solder volumes found in these newer technologies. Joint formation, grain structure and voiding issues are discussed along with intermetallic (IMC) growth on Copper and Nickel pads. Further understanding of microbump soldering behavior is critical to the mass production success of these newer technologies.
To read the complete tutorial, please click here for the PDF file