Cu3Sn-microporous copper composite joint for high-temperature die-attach applications. Issue 3 (4th October 2021)

• Record Type: Journal Article
• Authors: Pan, Zhen; Sun, Fenglian
• Is Part Of: Soldering & surface mount technology. Volume 34:Issue 3(2022)
• Page Start: 137
• Page End: 144
• Publication Date: 2021-10-04
• Subjects: Shear strength -- Aging -- Electrical properties -- Intermetallic alloys and compounds -- Thermal properties; Brazing -- Periodicals; Solder and soldering -- Periodicals; 671.5605
• DOI: 10.1108/SSMT-07-2021-0047
• Languages: English
• ISSNs: 0954-0911

Abstract

Abstract : Purpose: The purpose of this paper is to design a novel die-attach composite joint for high-temperature die-attach applications based on transient liquid phase bonding. Moreover, the microstructure, shear strength, electrical property, thermal conductivity and aging property of the composite joint were investigated. Design/methodology/approach: The composite joint was made of microporous copper and Cu3 Sn. Microporous copper was immersed into liquid Sn to achieve Sn-microporous copper composite structure for die attachment. By the thermo-compression bonding, the Cu3 Sn-microporous copper composite joint with a thickness of 100 µm was successfully obtained after bonding at 350 °C for 5 min under a low pressure of 0.6 MPa. Findings: After thermo-compression bonding, the resulting interconnection could withstand a high temperature of at most 676 °C, with the entire Sn transforming into Cu3 Sn with high remelting temperatures. A large shear strength could be achieved with the Cu3 Sn-microporous copper in the interconnections. The formed bondlines demonstrated a good electrical and thermal conductivity owing to the large existing amount of copper in the interconnections. Furthermore, the interconnection also exhibited excellent reliability under high temperature aging at 300 °C. Originality/value: This die-attach composite joint was suitable for power devices operating under high temperatures or other harsh environments.