Study of Bond Formation in Ceramic and Composite Materials Ultrasonically Soldered with Bi-Ag-Mg-Type Solder

Roman Kolenak; Tomas Melus; Jaromir Drapala; Peter Gogola; Matej Pasak

doi:10.3390/ma16082991

Study of Bond Formation in Ceramic and Composite Materials Ultrasonically Soldered with Bi-Ag-Mg-Type Solder

Materials (Basel). 2023 Apr 10;16(8):2991. doi: 10.3390/ma16082991.

Authors

Roman Kolenak¹, Tomas Melus¹, Jaromir Drapala², Peter Gogola¹, Matej Pasak¹

Affiliations

¹ Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, Jána Bottu No. 2781/25, 917 24 Trnava, Slovakia.
² Department of Non-Ferrous Metals, Refining and Recycling, FMT-Faculty of Materials Science and Technology, Technical University of Ostrava, 17. Listopadu 15, 708 33 Ostrava, Czech Republic.

Abstract

This research aimed to study a Bi-Ag-Mg soldering alloy and the direct soldering of Al₂O₃ ceramics and Ni-SiC composites. Bi11Ag1Mg solder has a broad melting interval, which mainly depends on the silver and magnesium content. The solder starts to melt at a temperature of 264 °C. Full fusion terminates at a temperature of 380 °C. The microstructure of the solder is formed by a bismuth matrix. The matrix contains segregated silver crystals and an Ag (Mg, Bi) phase. The average tensile strength of solder is 26.7 MPa. The boundary of the Al₂O₃/Bi11Ag1Mg joint is formed by the reaction of magnesium, which segregates in the vicinity of a boundary with a ceramic substrate. The thickness of the high-Mg reaction layer at the interface with the ceramic material was approximately 2 μm. The bond at the boundary of the Bi11Ag1Mg/Ni-SiC joint was formed due to the high silver content. At the boundary, there were also high contents of Bi and Ni, which suggests that there is a NiBi₃ phase. The average shear strength of the combined Al₂O₃/Ni-SiC joint with Bi11Ag1Mg solder is 27 MPa.

Keywords: Al2O3 ceramic; Bi solder; Ni–SiC substrate; soldering; ultrasonic soldering.

Grants and funding

This work was supported by the Agency for Support of Research and Development via contracts No. APVV-17-0025, APVV-21-0054, and VEGA project No. 1/0303/20: Research on Joining Metallic and Non-Metallic Materials for the Production of Semiconductor Parts.