Cu3Sn joint based on transient liquid phase bonding of Cu@Cu6Sn5 core–shell particles

Abstract

With the development of high-integration and high-power electronics, the lack of matching chip connecting materials that can withstand high temperatures has been a challenge. In this manuscript, a Cu@Cu6Sn5 core–shell bimetallic particles (approx. 1 μm in diameter) are successfully prepared and introduced as a new solder material for the packaging of power devices to obtain a Cu3Sn all-IMC solder joint. The joint consisted mainly of equiaxed Cu3Sn grains, and a small portion of columnar Cu3Sn grains. In columnar-type growth, Sn is the dominant diffusing species, which comes from the depletion of Sn in Cu6Sn5. The depleted Cu6Sn5 is transformed into columnar Cu3Sn. In equiaxed-type growth, Cu is the dominant diffusing species. Cu reacts with Cu6Sn5 to grow a Cu3Sn layer. This conclusion was confirmed by the orientation relationship. The equiaxed Cu3Sn grain nucleates at the Cu/Cu3Sn interface have an orientation relationship with the Cu substrate. Columnar Cu3Sn grains at the Cu6Sn5/Cu3Sn interface have an orientation relationship with Cu6Sn5.

Cu-Cu joint with Sn-58Bi/Porous Cu/Sn-58Bi transient liquid phase bonding under formic acid atmosphere

“…Transient liquid phase bonding (TLPB) has been developed for die-bonding joints capable of enduring higher working temperatures (Yang et al , 2023; Wang et al , 2023a). TLPB operates on the principle of a rapidly melting intermediate layer that then diffuses and reacts with the solid metal to be bonded, forming an intermetallic compounds (IMC) between the solid and liquid phases (Sun et al , 2022; Jiang et al , 2022; Zhong et al , 2015).…”

Interfacial Intermetallic Compounds Growth Kinetics and Mechanical Characteristics of Ga-Cu Interconnects Prepared Via Transient Liquid Phase Bonding

“…At present, given the challenges in the packaging and interconnection of electronic devices, a wide range of materials and processes are considered to address the challenges to enable future high-performance and reliable electronic products [1,2]. It is even more stringent for high-temperature applications under harsh and extreme conditions, particularly in the automotive, aerospace, and energy production sectors with recently significantly increased demands [3].…”