Research progress in diffusion barrier for advanced electronic packaging

Abstract

As the core of electric energy conversion, power devices have been developed rapidly in new electronic fields such as spacecraft, renewable energy vehicles, high-speed trains and submarine communication cables. The new generation of power devices have put forward higher, faster and more efficient requirements for advanced electronic packaging. However, the significant reduction of the solder joint size of chip interconnection leads to a sharp increase in the formation of intermetallic compounds (IMCs) within the solder joint, which poses a challenge to the reliability of the solder joint. In packaging structure, diffusion barrier layer plays an important role in the generation of intermetallic compounds. Therefore, the development of high reliability diffusion barrier layer has become one of the research concerns in the field of advanced electronic packaging. Herein, the research progress of diffusion barrier in advanced electronic packaging field in recent years was summarized based on different materials including elementary substance, binary compound, ternary compound, composite material and multi-layers. On this basis, three diffusion blocking mechanisms were summarized, including grain refinement of IMCs, segregation of alloying elements and suppression of Kirkendall voids. In the meanwhile, the failure mechanism of the barrier layer was analyzed.The effect of diffusion barrier on solder joint reliability was discussed. Finally, it was pointed out that the existing diffusion barrier research is still in the stage of manufacturing process and material performance exploration, and in the future, in-depth and systematic research can be carried out on high-entropy alloys, multi-physics coupling effects, failure and diffusion barrier mechanism disclosure.

Keywords

• advanced packaging
• intermetallic compound
• under bump metallization
• diffusion barrier property
• failure mechanism