Research & Development in Material Science

The Application of Phase Diagram for Interfacial Reactions in Electronic Packaging

  • Open or Close Yee Wen Yen*, Yu-Chun Li and Chin-Hung Lin

    Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taiwan

    *Corresponding author: Yee Wen Yen, Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan

Submission: February 26, 2018;Published: March 23, 2018

DOI: 10.31031/RDMS.2018.04.000594

ISSN: 2576-8840
Volume4 Issue4


The phase diagram investigation is basically scientific study of materials science and engineering. The basic materials knowledge, such as material thermodynamics and kinetic, phase transformation, and solid state diffusion can be used to explain the intermetallic compounds (IMCs) formed at the interface. Meanwhile, the phase diagram information is one of the important tools, as well. The phenomena in the interfacial reaction should be combined with the phase equilibrium information. Therefore, we can have a clear understanding of the interfacial reaction between the atomic diffusion mechanism and the final equilibrium condition. In the electronic packaging process, lead-free solders are Sn-based alloys, and the substrate is likely to be the Ni/Cu structure. During the soldering process, both Cu and Ni are rapidly dissolved into the molten solder, resulting in the concentration changes of Cu or Ni. The Cu concentration at the solder-joint would dramatically change before and after reflowing due to long heat-treatment aging or the solder-joint volume change. Professor Sinn-Wen Chen and Professor C. Robert Kao have report several studies on Cu concentration effect in the solder/ Cu couple and obtained widely response from the industry. The IMC growth at the Ni side and IMC precipitation in the solder are very sensitive to the Cu concentration and aging time. In this talk, we describe the relationship between the interfacial reactions and the corresponding phase diagrams for the above systems. The soldering society would understand the importance of the phase diagram in electronic package.

Keywords:Phase diagram; Intermetallic compound; Interfacial reaction; Electronic packaging; Soldering process

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