The Interfacial Reaction between Amorphous Ni-W-P Coating and Sn-58Bi Solder

Abstract

With the rapid development of the advanced electronic packaging field, the requirements for the connection between solder and Cu substrate are becoming increasingly stringent. Currently, the commonly used Ni-P diffusion barrier layer in the industry lacks long-term reliability, and its resistivity is higher than that of other substrates. This paper introduces the highly conductive metal element W to modify the binary Ni-P coating and prepares a ternary Ni-W-P coating through electrodeposition to improve this situation. The key parameters for the electrodeposition of ternary Ni-W-P are determined. The isothermal aging reaction of Ni-W-P with Sn-Bi solder at 100 °C was studied, and the results showed that, compared to the conventional Ni-P coating, the Ni-W-P barrier coating with higher W content has a much longer lifespan as a barrier layer and exhibits significantly better electrical conductivity. Additionally, the reaction mechanism between Ni-W-P and the Sn-Bi solder is proposed. This research presents a promising advancement in the development of barrier layers for electronic packaging, potentially leading to more reliable and efficient electronic devices. Introducing tungsten into the Ni-P matrix not only extends the lifespan of the coating but also enhances its electrical performance, making it a valuable innovation for applications requiring high conductivity and durability. This study could guide further investigations into the application of ternary coatings in various electronic components, paving the way for improved designs and materials in the semiconductor industry.

Keywords

• Ni-W-P
• diffusion barrier
• isothermal aging
• interfacial reaction